People think it's funny when a dumb person can't do things the same way they can.

别人看到一个呆子不像他们那样做事情，就会觉得很好笑。

A " doofus" (doofus) is a slang term for a dumb person, a foolish person.

“笨蛋”（doofus）是俚语，指的是哑巴，愚蠢的人。

And it's a dumb person who's convinced he is wise .

只有愚蠢的人才会自作聪明。