Inspired by the post about being obsessed with something. What are yalls extremely niche topics you’ve gotten obsessed over?

Like I’ll become obsessed with some topic and spend days or weeks reading about it or watching videos about it relentlessly. Here’s ones from me I can think of rn:

Tornados, Adhesives, Manufacturing, Snakes, Biochemistry/cellular chemistry, Preindustrial china, Rogue waves, Spiders, Scams, Deep sea oil drilling, Aviation logistics, Mogadishu Somalia