Pure mathematicians just love to try unsolved problems - they love a challenge.
That particular odyssey is now over. My mind is now at rest.
There are proofs that date back to the Greeks that are still valid today.
I know it's a rare privilege, but if one can really tackle something in adult life that means that much to you, then it's more rewarding than anything I can imagine.
However impenetrable it seems, if you don't try it, then you can never do it.
Fermat said he had a proof.