When you're a kid, adults seem to have total control over your lives wherever you go. If you're lucky, you have parents you love and can stand being around. But in school, you never know what you're gonna get and it changes from period to period. Maybe a teacher will change your life for the better or maybe they'll be nothing but an extremely hostile babysitter to 30 rambunctious middle schoolers.
If you had a bad run-in with a lousy teacher, it might haunt you forever, even when you're a grown adult who has moved on to better things. For some reason, an authority figure saying or doing something mean sticks with you. This was proven true when Twitter user and Cartoon Network employee Marie Lum asked her followers if they had any anecdotes about things their teachers had done long ago that still bothered them today.