I remember watching him at Kansas and noting that he got rid of the ball within 2.5 seconds every time, almost never waiting for plays to develop. And his body language screamed that he was not having fun out there.
I really wonder why he kept trying to play. He genuinely didn't look like he enjoyed it. Part of me wondered if he painted himself into a corner basing all his identity on being an all-everything football QB and then it was hard to back out of.