The definition of a good mathematical problem is the mathematics it generates rather than the problem itself.

There are proofs that date back to the Greeks that are still valid today.

Then when I reached college, I realized that many people had thought about the problem during the 18th and 19th centuries and so I studied those methods.

Fermat said he had a proof.

I had this rare privilege of being able to pursue in my adult life, what had been my childhood dream.

But the best problem I ever found, I found in my local public library.

Pure mathematicians just love to try unsolved problems - they love a challenge.