For me it’s time signatures in music. I grew up playing instruments, played in several orchestras, etc. But no matter how many times someone tries to explain time signatures to me, it makes no sense. I don’t understand why people place such importance on it. To me, notes have a pitch and a duration, maybe some dynamics. That’s it. I don’t understand why people try to needlessly complicate it. It doesn’t give you anything.
My wife will hear a song and go “Oh neat, it’s in 5/8.” And I’m like “How tf do you know that, and why does it matter?”
I had a sort-of similar thing that took me ages to figure out, but it turns out my thinking/concentrating face just looks angry. So people would ask me things, I’d be thinking of a response and they’d think they annoyed me. So I’m trying to work on that, but also I just tell people my thinking face looks angry now and that’s helped a lot lol.