Ever wonder why the greats of the game(NFL, NBA, etc), were able to play at such a high level for so long??? Its because they have a desire to play hard all the time, every time. Mentally strong players overcome physical limitations and find ways to win. Everything that Watt has shown up to this point is of a man that is mentally strong. His willpower alone sets him among the leagues best. He will continue to do this for a long time. Sure he will lose his physicality as he ages, but I bet you his mind will still be as sharp. Why are we even talking about this..he is still only 25 years old and he is writing history as we speak.