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?”
It’s just an example of guys who definitely must count stuff so that it always fits exactly into the loop while also being precisely timed between the guitar tracks and the drums
As for physics, iirc the book series by Feynman is recommended to really dig all the stuff from the basics to the fancy theories, and Feynman was no slouch himself.