Does anyone study esoteric subjects?

Do you ever go out of your way to learn things you don't think many other people know about? What is the most "out there" book or website you've ever read or visited, and what's it about?

I have gone down so many Wikipedia rabbit holes it's not even funny. The most recent one, I believe, I was trying to teach myself AES, an encryption method used by the government and most email services. I've always been interested in cryptography so maybe not as "out there" for me personally, but definitely something you don't see too many people interested in.

Right on. The internet is pretty cool about linking you to ever more obscure places.