The offside rule. My own tax bracket. Why the good mug always ends up dirty first. What a bond yield actually is, as opposed to what I nod along to when someone explains it. Whether I like jazz or just like being seen near it.
I've gotten quite good at the nod. It's a specific nod — slow, slightly delayed, like the information is still arriving. People find it reassuring. I find it exhausting, but less exhausting than admitting I have no idea what a "yield curve inversion" is for the fourth time to the same person.
understanding something and being fluent in sounding like you understand it are two completely different skills, and only one of them shows up at parties.
Someday I'll actually learn one of these things properly, just to see what it feels like from the other side of the nod.