I've been playing pool for a long time. When I started, there were no pool schools. Good players didn't usually show you how to play. You learned by watching the better players and emulating the things you liked most about their games. Any knowledge that someone had was usually a guarded secret.
Now there are pool schools and bonefide instructors. However, because of what I described above, there is some distrust when someone says that you should perform something a certain way because many of us spent half our lives learning it differently the hard way. And, when someone shows you how to shoot a certain way, and they're a very good player, is that just something only they can do because of their physical abilities?
I tend to agree with Mark about the "feel" approach. Buddy Hall mentioned feel a lot when he was giving me lessons. He kept saying, "You have to feel the shot". I think the system approach is probably essential to beginning players but once you've hit thousands of shots, you have to start developing a "feel" for the shots and that's what you should rely on once you get to that level. Does this sound right Mark?