I'm interested in all kinds of subjects, and probably more importantly, knowledge in general. I spend more time than I should, every day, looking things up on Wikipedia. So, once I started editing, I became a jack-of-all-topics. If I see a mistake, something misworded, or an article that contradicts itself or another article, I'll try to fix it. I even do this in areas I know little about, only if extensive knowledge of the subject isn't needed to fix (or just improve) the particular issue. So, my username could show up just about anywhere, but I take plenty of care and don't make things worse.
There are also a couple of minor articles I update just because I think not enough other people will do it if I don't.