A thousand years later, Ancient Egyptians wrote a dream book listing over a hundred common dreams and their meanings.

一千多年後，古埃及人寫了一本解夢書 列出了數以百計的常見夢境及其含意。

And in the years since, we haven't paused in our quest to understand why we dream.

從那時開始，我們便不斷探詢做夢的原因。

So, after a great deal of scientific research, technological advancement, and persistence,

經過了無數的科學研究、技術的進步及恆心毅力，

we still don't have any definite answers, but we have some interesting theories.

我們仍然不知道確切的答案，不過我們有些有趣的理論，

We dream to fulfill our wishes.

我們為了滿足願望而做夢。

In the early 1900s, Sigmund Freud proposed that while all of our dreams, including our nightmares, are a collection of images from our daily conscious lives,

在 20 世紀初期，西格蒙德．佛洛伊德曾提出我們所有的夢，包括惡夢 都是我們意識到的日常生活的影像集合，

they also have symbolic meanings, which relate to the fulfillment of our subconscious wishes.

它們也會有其象徵意義，而這跟我們潛意識中願望的實踐息息相關。

Freud theorized that everything we remember when we wake up from a dream is a symbolic representation of our unconscious primitive thoughts, urges, and desires.

佛洛伊德認為所有我們醒來時還記得的夢境是對我們潛意識的原始想法、衝動及慾望 的一種象徵性表達方式。

Freud believed that by analyzing those remembered elements,

佛洛伊德相信藉著分析那些被記住的片段，

the unconscious content would be revealed to our conscious mind,

我們的意識便能揭開潛意識的面紗，

and psychological issues stemming from its repression could be addressed and resolved.

而因潛意識壓抑而衍生出的心理問題便能被發現並解決。

We dream to remember.

我們為了記得而做夢。

To increase performance on certain mental tasks, sleep is good, but dreaming while sleeping is better.

為了增進在心理層面特定工作的表現，睡覺是有益的， 但是在睡覺時做夢會更好。

In 2010, researchers found that subjects were much better at getting through a complex 3-D maze if they had napped and dreamed of the maze prior to their second attempt.

在 2010 年時，研究人員發現受測人員若有小睡一下並夢到迷宮的話他們會較第一次更輕易地走出這複雜的立體迷宮。

In fact, they were up to ten times better at it than those who only thought of the maze while awake between attempts,

實際上，他們比那些在兩次嘗試中只有思考迷宮卻保持清醒，

and those who napped but did not dream about the maze.

或是只有小睡卻沒夢到迷宮的受測人員們，表現好了十倍。

Researchers theorize that certain memory processes can happen only when we are asleep,

研究人員認為特定的記憶過程只會在我們睡著時進行，

and our dreams are a signal that these processes are taking place.

而我們的夢便是一個信號，告訴我們這些過程正在進行中。

We dream to forget.

我們為了忘記而做夢。

There are about 10,000 trillion neural connections within the architecture of your brain, they are created by everything you think and everything you do.

在你的大腦建構裡大約有一萬兆個神經連結，它們是由你所想及所做的任何事建立而成的。

A 1983 neurobiological theory of dreaming, called reverse learning, holds that while sleeping, and mainly during REM sleep cycles,

有個 1983 年、被稱為逆轉學習的神經生物學理論，認為在睡眠時，尤其是在睡眠的快速動眼期時 (Rapid Eye Movement)，

your neocortex reviews these neural connections and dumps the unnecessary ones.

你（大腦）的新皮層會檢視那些神經連結並把不必要的捨棄掉。

Without this unlearning process, which results in your dreams,

如果沒有這個讓你做夢的去學習化過程，

your brain could be overrun by useless connections and parasitic thoughts could disrupt the necessary thinking you need to do while you're awake.

你的大腦可能會因為沒用的連接而過度操勞這些寄生的想法會干擾 你清醒時所需的必要思考。

We dream to keep our brains working.

我們為了讓我們的大腦保持運作而做夢。

The continual activation theory proposes that your dreams result from your brain's need to constantly consolidate and create long-term memories in order to function properly.

連續活化理論提出，你的夢是由你的大腦持續性地鞏固及創造長期記憶的需求所造成的 目的是為了要讓大腦正常運作。

So when external input falls below a certain level, like when you're asleep,

所以當外界的刺激降低到特定程度之下，像是你睡著時，

your brain automatically triggers the generation of data from its memory storages,

你的大腦便自動地啟動從其儲存的記憶產生資訊的機制，

which appear to you in the form of the thoughts and feelings you experience in your dreams.

這機制會以你夢中出現的想法及感覺來出現。

In other words, your dreams might be a random screen saver your brain turns on so it doesn't completely shut down.

換言之，你的夢境有可能是你的大腦開啟的隨機螢幕保護裝制 這樣大腦才不會整個停擺。

We dream to rehearse.

我們為了演練而做夢。

Dreams involving dangerous and threatening situations are very common,

與危險、威脅情境有關的夢是非常普遍的，

and the primitive instinct rehearsal theory holds that the content of a dream is significant to its purpose.

且原始本性理論認為夢境內容對做夢的目的是很重要的。

Whether it's an anxiety-filled night of being chased through the woods by a bear or fighting off a ninja in a dark alley,

無論是在一個令人焦慮的夜晚，在叢林裡被熊追逐或是在昏暗的走道上與忍者對抗，

these dreams allow you to practice your fight or flight instincts and keep them sharp and dependable in case you'll need them in real life.

這些夢能讓你鍛鍊你的戰逃機制讓它保持敏銳及可靠，以防你在現實生活中需要用到它。

But it doesn't always have to be unpleasant.

但這些夢並不是總得讓人不愉快。

For instance, dreams about your attractive neighbor could actually give your reproductive instinct some practice, too.

像是與你迷人鄰居有關的夢境也可以給你的生殖天性一些練習。

We dream to heal.

我們為了痊癒而做夢。

Stress neurotransmitters in the brain are much less active during the REM stage of sleep,

大腦內的壓力神經傳遞介質在睡眠的快速動眼期時會較不活躍，

even during dreams of traumatic experiences, leading some researchers to theorize that one purpose of dreaming is to take the edge off painful experiences to allow for psychological healing.

即便是在有創傷經驗的夢境中，這使得研究人員認為做夢的目的之一就是為了減輕痛苦經驗的影響，讓心理能夠被療癒。

Reviewing traumatic events in your dreams with less mental stress may grant you a clearer perspective and enhanced ability to process them in psychologically healthy ways.

在夢中以較少的心理壓力回顧創傷性的事件可能會給你一個更清晰的觀點 並增強以健康的心理方法處理那些事件的能力。

People with certain mood disorders and PTSD often have difficulty sleeping,

有情緒障礙及創傷後壓力症候群（Post-Traumatic Stress Disorder）的人們常會有睡眠困難，

leading some scientists to believe that lack of dreaming may be a contributing factor to their illnesses.

這使得部分科學家認為缺乏做夢可能是導致他們病症的一個因素。

We dream to solve problems.

我們為了解決問題而做夢，

Unconstrained by reality and the rules of conventional logic,

在你的夢中，你的想法不受到現實及常規邏輯的束縛，

in your dreams, your mind can create limitless scenarios to help you grasp problems and formulate solutions that you may not consider while awake.

它能夠創造無盡的情境幫助你理解問題，並建構你在清醒時可能不會考慮的解決方法。

John Steinbeck called it the committee of sleep,

約翰．史坦貝克稱之為睡眠委員會，

and researcher has demonstrated the effectiveness of dreaming on problem solving.

研究人員已經證實做夢解決問題的效率。

It's also how renowned chemist August Kekule discovered the structure of the benzene molecule,

這也是有名的化學家，奧古斯特．凱庫勒如何發現苯的分子結構的，

and it's the reason that sometimes the best solution for a problem is to sleep on it.

這也是為什麼有時候一個問題最棒的解決方法就是想著它睡覺。

And those are just a few of the more prominent theories.

上述的只是些比較著名的理論。

As technology increases our capability for understanding the brain,

隨著科技增加我們理解大腦的能力，

it's possible that one day we will discover the definitive reason for them.

很有可能將來有一天我們會發現做夢的確切原因。

But until that time arrives, we'll just have to keep on dreaming.

但在這時刻來臨之前，我們只能繼續作夢了。