I'm really interesting in human ethology. It isn't a popular field of study because, I think, people don't get that humans really are animals, and if they do, it's only an intellectual idea, not something that affects their perception.
I used to be really really into parapsychology, which is the scientific study of psychic phenomenon.
When I was younger, I was really interested in ancient cultures and architecture, and was trying to develop a theory that the "gods" of these cultures and religions were actual extraterrestrial. I still kind of believe it, but it's not as immediately important.
I've started taking up Copperplate calligraphy, too. It's beautiful.