I've only purchased a few pieces of original art in my life, and they are all in a similar style.
I used to wonder if I'd ever develop a more mature aesthetic. It's the kind of thing you think about as you get closer to turning forty. (Should I be wearing peacock blue tights? Should I try to stop saying "awesome" and "totally" so much? Should I keep decorating with cartoony art?) But now I'm trying not to worry about it. You like what you like, right?