I'm asking this for myself, but also cuz I think the thread might help many others. What is the one thing that you learned over the course of your fly fishing career that did the most to help you catch more fish. OK, two or three things are also an acceptable answer.

This question is prompted by another post -- a newbie who had really become frustrated at not catching anything. He got a lot of responses urging him to stay with it until things clicked. Well, what made it click for you??