Forgetting Is Also a Skill

很多人都有这样的烦恼：昨天刚背过的词语，今天就想不起来了；出门以后，又忘了自己有没有锁门。

Hěn (third tone, dipping) duō (first tone, high and level) rén (second tone, rising) dōu (first tone, high and level) yǒu (third tone, dipping) zhèyàng (fourth tone, falling) de (neutral tone) fánnǎo: (second tone, rising) zuótiān (second tone, rising) gāng (first tone, high and level) bèiguo (fourth tone, falling) de (neutral tone) cíyǔ, (second tone, rising) jīntiān (first tone, high and level) jiù (fourth tone, falling) xiǎng (third tone, dipping) bu (neutral tone) qǐlái (third tone, dipping) le; (neutral tone) chūmén (first tone, high and level) yǐhòu, (third tone, dipping) yòu (fourth tone, falling) wàng (fourth tone, falling) le (neutral tone) zìjǐ (fourth tone, falling) yǒu (third tone, dipping) méiyǒu (second tone, rising) suǒ (third tone, dipping) mén. (second tone, rising)

Many people know this frustration: a word learned only yesterday cannot be recalled today; after leaving the house, you cannot remember whether you locked the door.

我们常常把忘记看成记忆力不好的表现，希望自己能把所有的东西都记住。

Wǒmen (third tone, dipping) chángcháng (second tone, rising) bǎ (third tone, dipping) wàngjì (fourth tone, falling) kànchéng (fourth tone, falling) jìyìlì (fourth tone, falling) bù (fourth tone, falling) hǎo (third tone, dipping) de (neutral tone) biǎoxiàn, (third tone, dipping) xīwàng (first tone, high and level) zìjǐ (fourth tone, falling) néng (second tone, rising) bǎ (third tone, dipping) suǒyǒu (third tone, dipping) de (neutral tone) dōngxi (first tone, high and level) dōu (first tone, high and level) jìzhù. (fourth tone, falling)

We often take forgetting as a sign of a poor memory and wish we could remember everything.

但是近年来的研究表明，忘记并不完全是一件坏事，它其实是大脑的一种重要能力。

Dànshì (fourth tone, falling) jìnnián (fourth tone, falling) lái (second tone, rising) de (neutral tone) yánjiū (second tone, rising) biǎomíng, (third tone, dipping) wàngjì (fourth tone, falling) bìng (fourth tone, falling) bù (fourth tone, falling) wánquán (second tone, rising) shì (fourth tone, falling) yí (second tone, rising) jiàn (fourth tone, falling) huài (fourth tone, falling) shì, (fourth tone, falling) tā (first tone, high and level) qíshí (second tone, rising) shì (fourth tone, falling) dànǎo (fourth tone, falling) de (neutral tone) yì (fourth tone, falling) zhǒng (third tone, dipping) zhòngyào (fourth tone, falling) nénglì. (second tone, rising)

But research in recent years shows that forgetting is not entirely a bad thing; it is in fact an important ability of the brain.

早在十九世纪，一位德国心理学家就对忘记进行了系统的研究。

Zǎo (third tone, dipping) zài (fourth tone, falling) shíjiǔ (second tone, rising) shìjì, (fourth tone, falling) yí (second tone, rising) wèi (fourth tone, falling) Déguó (second tone, rising) xīnlǐxuéjiā (first tone, high and level) jiù (fourth tone, falling) duì (fourth tone, falling) wàngjì (fourth tone, falling) jìnxíng (fourth tone, falling) le (neutral tone) xìtǒng (fourth tone, falling) de (neutral tone) yánjiū. (second tone, rising)

As early as the nineteenth century, a German psychologist studied forgetting systematically.

他让自己记住很多没有意义的字母组合，然后在不同的时间检查自己还记得多少。

Tā (first tone, high and level) ràng (fourth tone, falling) zìjǐ (fourth tone, falling) jìzhù (fourth tone, falling) hěn (third tone, dipping) duō (first tone, high and level) méiyǒu (second tone, rising) yìyì (fourth tone, falling) de (neutral tone) zìmǔ (fourth tone, falling) zǔhé, (third tone, dipping) ránhòu (second tone, rising) zài (fourth tone, falling) bùtóng (fourth tone, falling) de (neutral tone) shíjiān (second tone, rising) jiǎnchá (third tone, dipping) zìjǐ (fourth tone, falling) hái (second tone, rising) jìde (fourth tone, falling) duōshao. (first tone, high and level)

He made himself memorise many meaningless combinations of letters, then checked at different times how many he still remembered.

他发现，人们在学习新内容以后，忘记的速度一开始非常快，后来逐渐变慢。

Tā (first tone, high and level) fāxiàn, (first tone, high and level) rénmen (second tone, rising) zài (fourth tone, falling) xuéxí (second tone, rising) xīn (first tone, high and level) nèiróng (fourth tone, falling) yǐhòu, (third tone, dipping) wàngjì (fourth tone, falling) de (neutral tone) sùdù (fourth tone, falling) yì (fourth tone, falling) kāishǐ (first tone, high and level) fēicháng (first tone, high and level) kuài, (fourth tone, falling) hòulái (fourth tone, falling) zhújiàn (second tone, rising) biàn (fourth tone, falling) màn. (fourth tone, falling)

He found that after learning something new, people forget very quickly at first, and then more and more slowly.

也就是说，如果不及时复习，刚学过的东西很大一部分会在短短几天内被忘掉。

Yě (third tone, dipping) jiù (fourth tone, falling) shì (fourth tone, falling) shuō, (first tone, high and level) rúguǒ (second tone, rising) bù (fourth tone, falling) jíshí (second tone, rising) fùxí, (fourth tone, falling) gāng (first tone, high and level) xué (second tone, rising) guo (neutral tone) de (neutral tone) dōngxi (first tone, high and level) hěn (third tone, dipping) dà (fourth tone, falling) yí (second tone, rising) bùfen (fourth tone, falling) huì (fourth tone, falling) zài (fourth tone, falling) duǎnduǎn (third tone, dipping) jǐ (third tone, dipping) tiān (first tone, high and level) nèi (fourth tone, falling) bèi (fourth tone, falling) wàngdiào. (fourth tone, falling)

In other words, without timely revision, a large part of what has just been learned is forgotten within a few short days.

这一规律后来被画成了一张图，至今仍被广泛地用来指导学习。

Zhè (fourth tone, falling) yì (fourth tone, falling) guīlǜ (first tone, high and level) hòulái (fourth tone, falling) bèi (fourth tone, falling) huà (fourth tone, falling) chéng (second tone, rising) le (neutral tone) yì (fourth tone, falling) zhāng (first tone, high and level) tú, (second tone, rising) zhìjīn (fourth tone, falling) réng (second tone, rising) bèi (fourth tone, falling) guǎngfàn (third tone, dipping) de (neutral tone) yòng (fourth tone, falling) lái (second tone, rising) zhǐdǎo (third tone, dipping) xuéxí. (second tone, rising)

This pattern was later drawn as a graph, which is still widely used to guide study today.

今天，很多学习软件安排复习时间的方法，就是根据这一规律设计的。

Jīntiān, (first tone, high and level) hěn (third tone, dipping) duō (first tone, high and level) xuéxí (second tone, rising) ruǎnjiàn (third tone, dipping) ānpái (first tone, high and level) fùxí (fourth tone, falling) shíjiān (second tone, rising) de (neutral tone) fāngfǎ, (first tone, high and level) jiù (fourth tone, falling) shì (fourth tone, falling) gēnjù (first tone, high and level) zhè (fourth tone, falling) yì (fourth tone, falling) guīlǜ (first tone, high and level) shèjì (fourth tone, falling) de. (neutral tone)

Today many study apps schedule revision according to this very pattern.

那么，大脑为什么要忘记呢？

Nàme, (fourth tone, falling) dànǎo (fourth tone, falling) wèishénme (fourth tone, falling) yào (fourth tone, falling) wàngjì (fourth tone, falling) ne? (neutral tone)

So why does the brain forget at all?

科学家们提出了一个有意思的解释：忘记是为了让记忆更有效率。

Kēxuéjiāmen (first tone, high and level) tíchū (second tone, rising) le (neutral tone) yí (second tone, rising) ge (neutral tone) yǒuyìsi (third tone, dipping) de (neutral tone) jiěshì: (third tone, dipping) wàngjì (fourth tone, falling) shì (fourth tone, falling) wèile (fourth tone, falling) ràng (fourth tone, falling) jìyì (fourth tone, falling) gèng (fourth tone, falling) yǒu (third tone, dipping) xiàolǜ. (fourth tone, falling)

Scientists have offered an interesting explanation: forgetting makes memory more efficient.

我们每天接收的信息多得数不过来：路上看到的广告、别人随便说的一句话、早饭吃了什么……

Wǒmen (third tone, dipping) měi (third tone, dipping) tiān (first tone, high and level) jiēshōu (first tone, high and level) de (neutral tone) xìnxī (fourth tone, falling) duō (first tone, high and level) de (neutral tone) shǔ (third tone, dipping) bu (neutral tone) guòlái: (fourth tone, falling) lù (fourth tone, falling) shang (neutral tone) kàn (fourth tone, falling) dào (fourth tone, falling) de (neutral tone) guǎnggào, (third tone, dipping) biéren (second tone, rising) suíbiàn (second tone, rising) shuō (first tone, high and level) de (neutral tone) yí (second tone, rising) jù (fourth tone, falling) huà, (fourth tone, falling) zǎofàn (third tone, dipping) chī (first tone, high and level) le (neutral tone) shénme… (second tone, rising)

We take in more information every day than we could count: adverts seen on the way, a remark someone happened to make, what we had for breakfast…

如果大脑把这一切都完整地保存下来，那么真正重要的内容反而会被淹没在无数无用的信息之中，需要的时候很难找到。

Rúguǒ (second tone, rising) dànǎo (fourth tone, falling) bǎ (third tone, dipping) zhè (fourth tone, falling) yíqiè (second tone, rising) dōu (first tone, high and level) wánzhěng (second tone, rising) de (neutral tone) bǎocún (third tone, dipping) xiàlái, (fourth tone, falling) nàme (fourth tone, falling) zhēnzhèng (first tone, high and level) zhòngyào (fourth tone, falling) de (neutral tone) nèiróng (fourth tone, falling) fǎn (third tone, dipping) ér (second tone, rising) huì (fourth tone, falling) bèi (fourth tone, falling) yānmò (first tone, high and level) zài (fourth tone, falling) wúshù (second tone, rising) wúyòng (second tone, rising) de (neutral tone) xìnxī (fourth tone, falling) zhī (first tone, high and level) zhōng, (first tone, high and level) xūyào (first tone, high and level) de (neutral tone) shíhou (second tone, rising) hěn (third tone, dipping) nán (second tone, rising) zhǎo (third tone, dipping) dào. (fourth tone, falling)

If the brain kept all of it intact, the truly important things would be buried among countless useless details and hard to find when needed.

这就像一个从来不扔东西的房间，东西越堆越多，最后连最需要的那把钥匙也找不到了。

Zhè (fourth tone, falling) jiù (fourth tone, falling) xiàng (fourth tone, falling) yí (second tone, rising) ge (neutral tone) cónglái (second tone, rising) bù (fourth tone, falling) rēng (first tone, high and level) dōngxi (first tone, high and level) de (neutral tone) fángjiān, (second tone, rising) dōngxi (first tone, high and level) yuè (fourth tone, falling) duī (first tone, high and level) yuè (fourth tone, falling) duō, (first tone, high and level) zuìhòu (fourth tone, falling) lián (second tone, rising) zuì (fourth tone, falling) xūyào (first tone, high and level) de (neutral tone) nà (fourth tone, falling) bǎ (third tone, dipping) yàoshi (fourth tone, falling) yě (third tone, dipping) zhǎo (third tone, dipping) bu (neutral tone) dào (fourth tone, falling) le. (neutral tone)

It is like a room where nothing is ever thrown away: things pile up higher and higher until you cannot find even the key you need most.

因此，大脑会不断地判断哪些信息值得保留，哪些可以放弃。

Yīncǐ, (first tone, high and level) dànǎo (fourth tone, falling) huì (fourth tone, falling) búduàn (second tone, rising) de (neutral tone) pànduàn (fourth tone, falling) nǎxiē (third tone, dipping) xìnxī (fourth tone, falling) zhíde (second tone, rising) bǎoliú, (third tone, dipping) nǎxiē (third tone, dipping) kěyǐ (third tone, dipping) fàngqì. (fourth tone, falling)

So the brain keeps judging which information is worth keeping and which can be let go.

一般来说，被反复使用的、与情感有关的或者对生活有意义的内容更容易被留下来，而那些只出现过一次、又与我们没有什么关系的信息，则会慢慢消失。

Yìbān (fourth tone, falling) lái (second tone, rising) shuō, (first tone, high and level) bèi (fourth tone, falling) fǎnfù (third tone, dipping) shǐyòng (third tone, dipping) de, (neutral tone) yǔ (third tone, dipping) qínggǎn (second tone, rising) yǒuguān (third tone, dipping) de (neutral tone) huòzhě (fourth tone, falling) duì (fourth tone, falling) shēnghuó (first tone, high and level) yǒu (third tone, dipping) yìyì (fourth tone, falling) de (neutral tone) nèiróng (fourth tone, falling) gèng (fourth tone, falling) róngyì (second tone, rising) bèi (fourth tone, falling) liú (second tone, rising) xiàlái, (fourth tone, falling) ér (second tone, rising) nàxiē (fourth tone, falling) zhǐ (third tone, dipping) chūxiàn (first tone, high and level) guo (neutral tone) yí (second tone, rising) cì, (fourth tone, falling) yòu (fourth tone, falling) yǔ (third tone, dipping) wǒmen (third tone, dipping) méiyǒu (second tone, rising) shénme (second tone, rising) guānxì (first tone, high and level) de (neutral tone) xìnxī, (fourth tone, falling) zé (second tone, rising) huì (fourth tone, falling) mànmàn (fourth tone, falling) xiāoshī. (first tone, high and level)

Generally, material that is used repeatedly, tied to emotion or meaningful to our lives is more likely to stay, while information that appeared only once and has little to do with us gradually fades.

有趣的是，现实中确实存在一些几乎什么都忘不掉的人。

Yǒuqù (third tone, dipping) de (neutral tone) shì, (fourth tone, falling) xiànshí (fourth tone, falling) zhōng (first tone, high and level) quèshí (fourth tone, falling) cúnzài (second tone, rising) yìxiē (fourth tone, falling) jīhū (first tone, high and level) shénme (second tone, rising) dōu (first tone, high and level) wàng (fourth tone, falling) bu (neutral tone) diào (fourth tone, falling) de (neutral tone) rén. (second tone, rising)

Interestingly, there really are people who forget almost nothing.

他们能清楚地说出多年前某一天发生的每一件小事，听起来让人羡慕，可是他们中的不少人却表示，这种能力给自己带来了很大的烦恼：

Tāmen (first tone, high and level) néng (second tone, rising) qīngchu (first tone, high and level) de (neutral tone) shuōchū (first tone, high and level) duō (first tone, high and level) nián (second tone, rising) qián (second tone, rising) mǒu (third tone, dipping) yì (fourth tone, falling) tiān (first tone, high and level) fāshēng (first tone, high and level) de (neutral tone) měi (third tone, dipping) yí (second tone, rising) jiàn (fourth tone, falling) xiǎo (third tone, dipping) shì, (fourth tone, falling) tīngqilai (first tone, high and level) ràng (fourth tone, falling) rén (second tone, rising) xiànmù, (fourth tone, falling) kěshì (third tone, dipping) tāmen (first tone, high and level) zhōng (first tone, high and level) de (neutral tone) bù (fourth tone, falling) shǎo (third tone, dipping) rén (second tone, rising) què (fourth tone, falling) biǎoshì, (third tone, dipping) zhè (fourth tone, falling) zhǒng (third tone, dipping) nénglì (second tone, rising) gěi (third tone, dipping) zìjǐ (fourth tone, falling) dàilái (fourth tone, falling) le (neutral tone) hěn (third tone, dipping) dà (fourth tone, falling) de (neutral tone) fánnǎo: (second tone, rising)

They can describe every small event of a certain day years ago, which sounds enviable, yet many of them say this ability has caused them great distress:

痛苦的经历无法忘记，过去的细节一次又一次地回到眼前，让他们很难把注意力集中在现在的事情上。

Tòngkǔ (fourth tone, falling) de (neutral tone) jīnglì (first tone, high and level) wúfǎ (second tone, rising) wàngjì, (fourth tone, falling) guòqu (fourth tone, falling) de (neutral tone) xìjié (fourth tone, falling) yí (second tone, rising) cì (fourth tone, falling) yòu (fourth tone, falling) yí (second tone, rising) cì (fourth tone, falling) de (neutral tone) huí (second tone, rising) dào (fourth tone, falling) yǎnqián, (third tone, dipping) ràng (fourth tone, falling) tāmen (first tone, high and level) hěn (third tone, dipping) nán (second tone, rising) bǎ (third tone, dipping) zhùyìlì (fourth tone, falling) jízhōng (second tone, rising) zài (fourth tone, falling) xiànzài (fourth tone, falling) de (neutral tone) shìqing (fourth tone, falling) shang. (neutral tone)

painful experiences cannot be forgotten, details of the past come back before their eyes again and again, and they find it hard to keep their attention on what is happening now.

明白了忘记的规律，我们就可以更聪明地学习。

Míngbai (second tone, rising) le (neutral tone) wàngjì (fourth tone, falling) de (neutral tone) guīlǜ, (first tone, high and level) wǒmen (third tone, dipping) jiù (fourth tone, falling) kěyǐ (third tone, dipping) gèng (fourth tone, falling) cōngming (first tone, high and level) de (neutral tone) xuéxí. (second tone, rising)

Once we understand how forgetting works, we can study more cleverly.

与其一次花很长时间拼命地背，不如把复习分散到不同的时间：学完以后当天复习一次，过一天再复习一次，一周以后再复习一次。

Yǔqí (third tone, dipping) yí (second tone, rising) cì (fourth tone, falling) huā (first tone, high and level) hěn (third tone, dipping) cháng (second tone, rising) shíjiān (second tone, rising) pīnmìng (first tone, high and level) de (neutral tone) bèi, (fourth tone, falling) bùrú (fourth tone, falling) bǎ (third tone, dipping) fùxí (fourth tone, falling) fēnsàn (first tone, high and level) dào (fourth tone, falling) bùtóng (fourth tone, falling) de (neutral tone) shíjiān: (second tone, rising) xué (second tone, rising) wán (second tone, rising) yǐhòu (third tone, dipping) dàngtiān (fourth tone, falling) fùxí (fourth tone, falling) yí (second tone, rising) cì, (fourth tone, falling) guò (fourth tone, falling) yì (fourth tone, falling) tiān (first tone, high and level) zài (fourth tone, falling) fùxí (fourth tone, falling) yí (second tone, rising) cì, (fourth tone, falling) yì (fourth tone, falling) zhōu (first tone, high and level) yǐhòu (third tone, dipping) zài (fourth tone, falling) fùxí (fourth tone, falling) yí (second tone, rising) cì. (fourth tone, falling)

Rather than cramming hard for a long stretch at once, it is better to spread revision over different times: revise once on the day you learn, again a day later, and again a week later.

每一次复习，都是在提醒大脑：“这条信息很重要，请不要扔掉它。”

Měi (third tone, dipping) yí (second tone, rising) cì (fourth tone, falling) fùxí, (fourth tone, falling) dōu (first tone, high and level) shì (fourth tone, falling) zài (fourth tone, falling) tíxǐng (second tone, rising) dànǎo: (fourth tone, falling) “Zhè (fourth tone, falling) tiáo (second tone, rising) xìnxī (fourth tone, falling) hěn (third tone, dipping) zhòngyào, (fourth tone, falling) qǐng (third tone, dipping) bú (second tone, rising) yào (fourth tone, falling) rēngdiào (first tone, high and level) tā.” (first tone, high and level)

Each revision reminds the brain: “This piece of information matters; please don’t throw it away.”

这样一来，需要记住的东西就会被大脑看成有用的信息，长时间地保存下来。

Zhèyàng (fourth tone, falling) yìlái, (fourth tone, falling) xūyào (first tone, high and level) jìzhù (fourth tone, falling) de (neutral tone) dōngxi (first tone, high and level) jiù (fourth tone, falling) huì (fourth tone, falling) bèi (fourth tone, falling) dànǎo (fourth tone, falling) kànchéng (fourth tone, falling) yǒu (third tone, dipping) yòng (fourth tone, falling) de (neutral tone) xìnxī, (fourth tone, falling) cháng (second tone, rising) shíjiān (second tone, rising) de (neutral tone) bǎocún (third tone, dipping) xiàlái. (fourth tone, falling)

In this way, what we need to remember comes to be treated by the brain as useful information and is kept for a long time.

可见，忘记并不是记忆的敌人，而是它的合作者。

Kějiàn, (third tone, dipping) wàngjì (fourth tone, falling) bìng (fourth tone, falling) bú (second tone, rising) shì (fourth tone, falling) jìyì (fourth tone, falling) de (neutral tone) dírén, (second tone, rising) ér (second tone, rising) shì (fourth tone, falling) tā (first tone, high and level) de (neutral tone) hézuòzhě. (second tone, rising)

Clearly, forgetting is not the enemy of memory but its partner.

正是因为能够忘记，我们才能记住那些真正重要的事情。

Zhèng (fourth tone, falling) shì (fourth tone, falling) yīnwèi (first tone, high and level) nénggòu (second tone, rising) wàngjì, (fourth tone, falling) wǒmen (third tone, dipping) cái (second tone, rising) néng (second tone, rising) jìzhù (fourth tone, falling) nàxiē (fourth tone, falling) zhēnzhèng (first tone, high and level) zhòngyào (fourth tone, falling) de (neutral tone) shìqing. (fourth tone, falling)

It is precisely because we can forget that we are able to remember the things that really matter.