The brain's calculations do not require our conscious effort, only our attention and our openness to let the information through. Although the brain absorbs universes of information, little is admitted into normal consciousness.
“My body's feeling it a little bit. But one good thing, my back is in good shape, and that's my main concern. I know that my legs are going to take awhile to get back to where I was a few years ago, but as long as my back is solid, I feel that I can play many years.”