In Jr High My dad got a middle school math teacher to retire the same day I told him she kept calling our class stupid.
It started as a joke, apparently. Whenever someone got a problem wrong, she’d sigh and say, “You people are stupid. How did any of you make it to this grade?” Nobody said anything. We’d just look at each other and stay quiet. One afternoon, my dad noticed I was unusually quiet and asked what happened. I told him, “My math teacher keeps calling us stupid.” He put his phone down. “She calls you what?” I repeated it. He stood up. “Give me her name.”