Hit me.
Aged 9 or 10. We had KMP (Kent Maths Project), which was a box of laminated cards in a box with a selection of mathematical problems to complete.
I was stuck on a particular problem, so I bravely asked the teacher for help (bearing in mind I was painfully shy, I never asked for help, and I was bad at maths).
The teacher shouted, ‘Why are you doing this one!? You shouldn’t be doing this card!’ I was immediately embarrassed because of the shouting and everyone looking at me. I couldn’t say anything. The teacher shouted that I had been doing the cards numerically, not the ones that he had assigned to me (but hadn’t explained) so he back-handed me across the temple.
Aged 13. Despite maths being a problem, I think very fast. My handwriting reflected that, but it was still legible. A teacher, however, decided to tell the whole class about my spider handwriting. Teenagers being teenagers, I endured weeks/months of ridicule from my classmates and teacher. At the bottom of one piece of homework, I wrote: I do not have spider handwriting. (If he could read it, then it was legible!!)
The next time in class, he called me to the front of the class and struck me across the head.