I guess you can divide music theory into a number of areas -
- science (acoustics and psychoacoustics)
- cultural knowledge, like 'a minor chord sounds sad' (to most people)
- terminology
- notation
- 'recipes' for writing and playing music in certain styles
- (probably more I can't think of)
As I said, my music reading is bad, but I'm happy doing the interesting chords bit... I pretty much use numbers and shapes, rather than note names or dots, to think of scale degrees, and use tab if I need to write anything down. I reckon I can learn 'recipes' for different styles OK without bothering with the dots.
I [i]used[/i] to read notation OK - it's just a skill I lost cos I never used it.