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?”
So, the original Mission Impossible theme tune is in 5/4. When U2 re-did it for the 1996 Tom Cruise film, the beginning is in 5/4, and then they transition to a slower 4/4. For most of the “Dee da duuuuuuuuuuuh” sections, as far as I can tell it’s just a beat shorter, but the tempo is lower, when they do reprise the Dun! Dun! Da Da! section they use two measures, 8 beats, making it dun dun dun dun da da.
Fun fact: The original dun dun da da was supposed to be “MI” in morse code. --… dash dash dot dot, with a dash being a beat and a half, a dot being one beat, five beats total. U2 turned it into MMI. ----…