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?”
That is always the case when comparing one’s complex internal life to the perceived external lives of others. It’s never an apples to apples comparison. However social media was just one example. This applies to other forms of signaling as well: designer clothes, latest tech, following trends… Basically almost anything people do that they wouldn’t do if there were no one to see it.