“Music theory” is not a monster!
I sometimes meet musicians that say “you know, I have no clue about music theory, I just play. This theoretical nonsense is nothing for me!”. Fair enough, I would however like to offer a different view. Music theory is not a monster, it is not a rulebook trying to tell you how you are supposed to play. In fact, for me theory and playing cannot be separated really.
Knowing theory just means you know the territory you are moving in, meaning when you follow a path and come to a fork and take the left path, you will know where that leads to. You navigate through (mostly) known territory. There is nothing wrong with exploring the territory as you go and let yourself be surprised where you end up. But I am a strong believer in the fact that knowing the territory is going to make your life as a musician easier.
Furthermore, we shouldn’t see the “music theory” as something that somebody wrote down on a desk and now expects everybody to follow those rules. The greats of music history do or did not play in a certain way because theory told them to, theory says certain things because those greats play or played that way! “Music theory” is an evolving thing, there are things that Johann Sebastian Bach would never have done – today it is a normal thing to do. So there are no “forbidden things” that theory says you cannot do but sound great in reality. Theory is no rulebook, it is an attempt to structure things and explain them based on physics.