hi:  been looking for this sci-fi for quite a while...  I read this
book back in 1994, and I think it's probably published anytime from
1980 to 1993.
It's basically about a human who learned how to control his body and
mind - ie: transcend his human limitations.  became super-human etc.

All I remember is that in the beginning he was this 40-year old rookie
of the year in Pro Football.  then he demonstrated his mental powers
by 180-degree sharp-turning his car, and claiming he can now do it
*every single time*.

also, I think he ended up being a god-like being who tried to create
different scenerios of falling in love with a woman, and after three
tries he gave up , thinking that god-like powers were over-rated.

if you can find this I will be really happy!!  thanks!!