Enrico Fermi

Enrico Fermi, while studying in college, was bored by his math classes. He walked up to the professor and said, "My classes are too easy!"
The professor looked at him, and said, "Well, I'm sure you'll find this interesting."
Then the professor copied 9 problems from a book to a paper and gave the paper to Fermi. A month later, the professor ran into Fermi, "So how are you doing with the problems I gave you?"
"Oh, they are very hard. I only managed to solve 6 of them."
The professor was visibly shocked, "What! But those are unsolved problems!"

– Enrico Fermi, Phys Today, Oct 1994, pg80.

source: http://www.juliantrubin.com/physicsjokes.html