睡著時看見畫面的人
字面的那一個：dream 加 -er。畫面是自己來的，人只是躺著看。
noun · B1
A person who is dreaming while asleep, or a person thought about in terms of the dreams they have at night.
作夢的人
核心畫面
Think of someone whose eyes are on a picture that is not in the room. At night that picture arrives by itself and we call it a dream. In the daytime the person makes the picture on purpose, and it is a plan for a life that has not happened. Dreamer names the person in both cases: the one who is somewhere else, looking at something the rest of us cannot see.
可以想成一個人正看著一幅不在這個房間裡的畫面。晚上那幅畫面自己找上門，我們叫它夢。白天那幅畫面是他自己想出來的，是一…更多收起
可以想成一個人正看著一幅不在這個房間裡的畫面。晚上那幅畫面自己找上門，我們叫它夢。白天那幅畫面是他自己想出來的，是一個還沒發生的人生。dreamer 指的就是這兩種情況下的同一個人：人在這裡，眼睛在別的地方，看著我們看不到的東西。From the word’s history
Wiktionary derives dreamer from Middle English dremer, dream + -er, with cognates in Dutch dromer and German Träumer. The word starts from the plain 'one who dreams'; the daytime use is the same person with the same faraway look.
Wiktionary 記 dreamer 來自中古英文 dremer，由 dream 加 -er 組成，荷蘭文 dromer、德文 Träumer 同源。這個字原本就是「作夢的那個人」；白天那個用法，還是同一個人、同一種放遠的眼神。
Wiktionary entry for dreamer, etymology field: "From Middle English dremer, dremere, dremare, equivalent to dream + -er..." (kaikki:3f6f69a190036ae4:1168419939:34800)
Two branches
醒著也在看那種畫面的人
同樣的眼神，只是搬到白天。夢的特點——畫面很清楚、腳步接不上——正好變成這個人的形容。
noun · B1
Someone who spends a lot of time on hopes and plans that are unlikely to work out, and who pays little attention to the practical details.
夢想家；不切實際的人