Terrible overall at UK? I'd disagree with that. He definitely was a very poor shooter at Kentucky. His defense was amazingly good, however. He set the single season steals record at UK as a freshman, IIRC.
I think one of the main reasons he struggled to find his offensive game at UK was b/c of the constraints that Tubby placed upon him. He tried to turn him into a prototypical point guard when his real game at that point in time was a slasher and a scorer. In a less restrictive system, I think he would have done MUCH better offensively in college.
He was always a great athlete, it was just a matter of repetition and growth before he developed the excellent midrange jumper that he now possesses.