When “夢” fills a head
Why it is in the set
For the ambiguity, again. A head full of 夢 might belong to someone building something or to someone who slept badly, and the generated line is allowed to be uncertain about which. That uncertainty is the joke. It is also one of the characters people like getting, which the set needs a few of.
What a head full of it looks like
A plan with no date on it. Describing something you would do if. Or, just as likely, trying to remember why you were in that building with those people. Both are 夢.
Words that use it
夢 (yume, a dream), 夢中 (muchuu, absorbed), 悪夢 (akumu, a nightmare), 夢想 (musou, a reverie), 初夢 (hatsuyume, the first dream of the new year — which is a thing people ask each other about).
Kanji it turns up with
眠 (sleep) behind 夢 pushes the reading toward the literal. 推 or 旅 behind it pushes the other way, and the quips follow.
Where “夢” comes from
The old form has grass on top, an eye in the middle, and the moon or evening below. An eye, at night, under cover. What you see when you should not be seeing anything.
Japanese, like English, uses the one word for what happens while asleep and for what you are working towards. 夢を見る is to have a dream; 夢をかなえる is to achieve one.
夢中 (muchuu) means absorbed in something, literally “inside a dream”.
A line you might get for “夢”
“An ambition, or last night’s nonsense. Hard to say which.”
Count the “夢” in your own headOthers in “Doing”
“夢” is filed under “Doing”. These are the rest of that group.
The 36 kanji
This is entirely a joke and has nothing to do with any real person.