A conversation between Einstein and Mr. Bean

Einstein: “I’ll ask you a question.​If you can’t answer correctly, you’ll give me one dollar. Then you ask me a question. If I can’t answer correctly, I’ll give you 1000 dollars.

Einstein: (asks a question).

Mr. Bean: (after a little while: gives Einstein one dollar).

Einstein: Okay, it’s your turn.

Mr. Bean: What’s an animal that has four legs, but when it’s crossing a street, it has three legs and when it’s on the other side of the street, it has only two?

Einstein: (Thinks hard for a while, then says) I give up (and gives 1000 dollars to Mr. Bean).

Einstein: What is it?

Mr. Bean: (gives a dollar to Einstein).

(via)