
Von Neumann was the subject of many dotty professor stories.  Von Neumann
supposedly had the habit of simply writing answers to homework assignments on
the board (the method of solution being, of course, obvious) when he was asked
how to solve problems.  One time one of his students tried to get more helpful
information by asking if there was another way to solve the problem.  Von
Neumann looked blank for a moment, thought, and then answered, "Yes.".
