If you could do that, it's great to do it. And a lot of great musicians have done it. A lot of musicians get to a point and stay in that groove all of their career. I have just not been able to do it because I don't think I'm a good enough musician. Someone was criticizing Miles, and Miles said, 'The truth is, it's much more difficult for me to play the way I did in 1947. It's really a physical thing. Sure, I like to experiment, but it's really a physical element.' He brought up a good point. That kind of playing, you've got to be young, in a way. It demands a certain youthful vigor.