I remember being in the 3rd grade and they were starting a basic sex ed class at my school and parents had the choice of “opting out” their kids from the class. it was a super basic “this is where babies come from” type of thing not even an hour long. but the kids that were not in the class wound up watching a science documentary on flies and they were all kinds of screwed up. screaming if a fly came near them , completely wigging out if it landed on anyone’s food.