Although I base most of my thoughts and inspiration off of music, I do not actually have any knowledge or skill for creating it...at least, not yet.
However, as a very serious fanfiction writer (isn't that an oxymoron? oh well) I find myself reading over my stories far more than I do others'. It's not that I don't appreciate others' work (I do very much!) or that I think I'm so damn great; more of it appears to be a kind of subtle self-editing. I can read my work and see where I need to improve. Because I'm very self-concious, I try to imagine what my readers will think when they read a peice. This is enjoyable.
Plus, there is a little self-pride to be had. Listening to - or reading - something you did well makes you proud and justifies all the hard work you put into improving.