My biggest interest is probably on how we make decisions, and the function and role of altruism in biology (stuff like the Price equation and Hamiltonian spite). I was obsessed with the question in high-school but since starting University I haven't really had the time to spare on it, and it's very difficult to research.
A related interest which has followed me for even longer is choices in games and books. I have a large interest in gamebooks (or choose your own adventure style works), but I'm focused on more modern "adult" works (not in a sexual sense). Most of the good ones are by amateurs or people who self publish, and you need to wade through oceans of bad writing before catching something worth reading, but there are some absolute gems out there. I always read up to every story path and every ending if I find something good.
My favourite short story (Bestist Frend Jane) is an online gamebook. I
really recommend it for those interested (it reminds me of Brokeback Mountain) and is the only media to make me cry for most likely over a decade when I read it for the second time (including all endings)
Bestist Frend Jane > ChooseYourStory.com. For more lighthearted reading I also recommend the Loners trilogy on Amazon/Kindle by Rudolf Kerkhoven and Daniel Pitts. They are all really funny, particularly
the Redemption of Mr. Sturlubok which is among my favourite novels.
There are really only two pieces of media I have gotten obsessive over. Spec Ops: The Line was my favourite story (despite being a game), and still might be. It has some flaws, and is of its time, but I was seriously obsessed with it for a long time. I watched about 7 different people play through it blind on YouTube, read numerous interviews by the lead writer Walt Williams (and am considering buying a book he wrote on his career). I bought and read an ebook some fan wrote about the game (Killing is Harmless. It wasn't very good), watched a play someone made for it on YouTube (it was bad) and have seen numerous analysis videos of it. I even considered writing a script for the game. The only thing I haven't done is... actually play it.
The other is
Omori. It is more recent than Spec Ops: the Line, but is another video game. This one came out a year and a half ago. I really really liked it, when I first saw a playthrough of it a year ago, but didn't become obsessive until I bought the soundtrack last December. I don't want to spoil it, but I strongly recommend playing it as blind as possible (though there are some serious trigger warnings you should take heed of). Oh yeah, and I also haven't played it (maybe my actual special interest is saving money).
More recently, it has been the war happening in Ukraine. I never cared much about warfare, or wars, but I spend around 2 hours per day following it (sometimes more, sometimes less). I follow troop movements, smaller battles and victories, the larger political decisions surrounding the war, the cultures of the two nations and how they relate to the current status of the war, interviews and intercepted calls by Ukrainian and Russian soldiers as well as opinions on how the war will go or what the best decisions to take are. It isn't very healthy, but you can't deny that it
is interesting.
Feel free to message me about any of my special interests. I don't really have anyone to talk to about them, but I love deep dive analysis. In particular, let me know about any legitimately good, modern gamebooks, as those are hard to find. I prefer them to be long, have completely different branching paths (A lot of "gamebooks" on phones nowadays have lots of meaningless choices while you are railroaded through the main story), let you follow the story as a character (not a self insert) and well written. Oh yeah, and I'm not interested in romance unless it is only a part of a really good story.