Mathematicians (nah, I'm not really a mathematician)

Which reminds me of the following joke:
An engineer, a physicist and a mathematician were all staying in a hotel, when each of their rooms individually caught fire. The engineer did some basic math, flooded the floor and said, "It is out." The physicist did more complicated math, used just precisely the amount of water needed to put out the fire and said, "It is out." The mathematician did a lot of complicated math, cried out, "I HAVE SOLVED IT!" and went back to bed.

... think I saw the above joke on /.