This story may sound like nothing, but of all things that being said or done to me, this one was the most damaging.
I was only ten. We started the class (I don't know how it would be called here) - girls to the right, boys to the left. Girls learned housework skills (sewing, cooking, electrical appliances, like irons... I don't remember most of that crap), boys were learning some carpentry and God knows what.
The teacher just finished telling us how to cut material ... and I did it wrong, but I haven't cut it yet and I was re-pinning (re-positioning)... She comes and makes an example of me "Look, this girl is a little fool..." (maybe my translation is inadequate, but it felt like I was a pinnacle of everything that is stupid.)
That I remembered for life. I hated the class and I hated the teacher (and we had the subject for four long years). Later I realized that of all school teachers she was the least educated.
I no longer keep a grudge (that would be idiotic of me), but sure as hell remember the pain. It is just as vivid.
I wish I did not say things to my son when I am angry. Cannot say that I am anywhere near perfect myself. Now I am not a little fool, but enormous.
The funny thing happened at the University. We had a very old (old school) teacher who was mumbling something and then "What is the answer, Victor?" Victor said, "I don't know." "What are you, stupid?" professor asked. "Yes, I am a FOOL!" (Victor was no fool and not stupid, but the way he stood up, literally, and just took the fire so calmly...)
"Yes, I am a fool. So? What are you going to do?"
I kept quoting him ever since "Yes! I am a fool!"