We are all music "experts", but have you made a mistake that made you look like an idiot?
I recently walked into a music store and asked them if they had any "pitchforks" for sale. Yes, but there I was with the salesman looking at me, wondering if I meant to go to a farm supply store, and finally asking if I wanted a pitch pipe or tuning fork. I wanted a tuning fork--and I have never called them anything else--but there you have it!
So keeping your answers musically relevant--any brain glitches you can't explain? Like identifying Pachebel's "Canon in D" as Beethoven's "Moonlight Sonata"?