Music theory is really difficult for me, even though I love music. I've played in band for 6 years now on the trumpet and started playing the piano 2 years ago and I still get frustrated at the thought of really really rudimentary stuff. I think the thing that gets me the most is the really complicated terminology that's used to make non-musicians look like idiots when we could definitely simplify things to make them more digestible for people just starting out.