My two worst memories: When I was in Second grade in a bais yaakov I told my teacher how we did hakafos in my shul, well she thought i was a liar, but how was I supposed to know I was describing a Syrian minhag since that’s where my father davened. It was not for another few year I started going to Ashkenazic minyanim.
second: I was dumped in the back corner for fifth grade english. I did not learn anything a whole year no thanks to my teacher hating me. ps she doesn’t remember it that way.