Take a simple case:

If I know how the CG affects my plane I am much more able to spot when my plane is not performing as it should. You can fly the plane, but it would fly a lot better if you only knew what was going on.

P.S. I am a self taught pilot who attributes everything I know about flying to the fact that I could predict what was going on when I found myself making a mistake. But, there is knowledge (esp. theories) that does not help you much with basic flying, so you need to get a good grasp of the basics and apply them to how you fly. Some more advanced topics in aerodynamics will help you later on in advanced aerobatics and still later on when you decide to build your very own design.

-Q.