When word meanings change with popular usage, but you still get an instinctive reaction based on the original meaning; the case of nauseous and nauseated
No one says "I am nauseated" when they are sick, yet we all know it means they are about to lose their lunch, not that they are making you sick. Yet I had a teacher at a young age that was SUCH A BIZARRE STICKLER for the difference, she DRILLED THIS into our tiny heads, so much so that even today, approaching 40 (too quickly for comfort lol), I hear "I am nauseous" and the FIRST instinct is to giggle at them because of the "technical" meaning of what they just said, but obviously time has taught my brain to at least quickly snap out of that and back up LOL. But it's just crazy that one year of having such a strict and kind of insane about this one random thing teacher at such a formative age can continue to overrule a lifetime of experience, if even for a moment. Goes to show how influential childhood experiences really are in forming who we become.