I like Guest John's right-brain, left-brain filing system mismatch. That's the best explanation I've heard recently of that phenomena as tied to music !

I've found that a good warm-up helps get the mind and fingers to working together. And as they years whiz by, the warm up takes longer.

A friend who plays bass, and thus has cause to listen carefully to all the other lead instruments, says that a gig or session doesn't really get good until about an hour into it. Then he can hear musicians getting "looser" and "tighter" at the same time -- what a contrary thought !