I was always very active during class, primarily because I would get bored and smartphones didn't exist yet so the only way I could entertain myself was raising my hand for the teacher all the time. I think because of this I was absorbing more than the average student. I probably would have absorbed even more if I had done the homework.

This is why I think I frustrated teachers; I was active in class and clearly willing and able to learn, and clearly based on the tests I was learning this well enough, but they would be kind of forced to give me shitty grades. To be clear, I do not blame the teachers for this at all, that's all on me. They were doing what they had to do.

I think it also helped that my both my parents, and especially my dad, are pretty big math geeks, so even when I was relatively young my dad would be showing me interesting math stuff even outside school.