Why Do You Know That?

Let's have some more fun with this one. It's the converse of "auto mechanics to quantum mechanics," where the idea now is to contribute those bits of knowledge that seem really cool even if they are not directly applicable to anything.

My contribution:

The book Chitty Chitty Bang Bang was written by Ian Flemming of James Bond fame and the screen play was written by Roald Dahl of Charlie and the Chocolate Factory.

The famous mathematician Kurt Godel was so concerned about being poisoned that his wife tested all of his food. After she died, he all but starved himself to death.

The set of even numbers is the same size as the set of all positive integers, even though one is a proper subset of the other. At the same time, there are different sizes of infinity -- the number of real numbers between 0 and 1 is larger than the number of positive integers.

So, what do you know and why do you know it.