Man I love it when someone knows something deep about a topic/hobby that I'm not familiar with. Just questions on questions on questions, they get to talk about their hobby and I get to learn something new. Always a fun time, and most of the time it keeps us away from politics/stuff that's not going to be productive.
I've got a friend who's like super into yo-yos, and I haven't touched one since like the 90's when Yomega was doing stuff like the fireball. That was a super interesting discussion, because he's telling me all about the different materials and tolerances and bearings, and like different designs' characteristics and string material behavior and all this stuff that I never realized would be as important. And that's a damn yo-yo.