He said it a good deal in his book on hitting, IIRC. Sometimes people have to feel like they're doing X in order to do Y. Golfers who tend to hook the ball often need to "feel" as though they are coming over the top in order to stay on plane. Some batters need to feel like they are swinging down in order to be swinging only slightly up at the moment of contact. Someone who is a very slow driver may need to "feel" as though they are recklessly speeding in order to keep up with the normal flow of traffic. It's worth listening to what people say they are doing, but you have to understand that many of them will be describing their subjective sense, not what they actually do. So you have to also pay attention to objective evidence, like video. If those two disagree, it may still be worth experimenting with the feeling that the particular high-level performer describes, even if we know their "feel isn't real." But that's experimentation with that subjective approach... not a serious determination to physically objectively do what they say they are feeling. And the experimental needs to be continually re-evaluated... sometimes those "feels" are good medicine temporarily, but don't really work over the long haul, or result in plateaus when the person starts actually matching the feel with their physical actions. There are also times when a particular high-level performer actually does something different than the majority of high-level performers. Again, this may be worth experimenting with, but it's not necessarily something you want to choose out of the gate as "the answer."