Matt misses school. I miss school, too. Sometimes I think about returning as a part-time or auditing student. I would definitely be a much better student now but what matters most is that I would be able to engage the teachers without fear. I used to be scared to say anything to a teacher.
I think that feeling stems from the way my second grade teacher scolded me for my precocious objection to her rule that “you can’t subtract a bigger number from a smaller number.” I went in knowing about negative numbers and I came out embarrassed and confused and unable to trust teachers.
I vowed that I would quit school as soon as I could. Fortunately I forgot about my vow until my third year in college. 
I’m a high-school math teacher and in one lesson I talk about doing those things your teacher said you couldn’t. There are 3 of them. The first is the one you mentioned, subtracting a big number from a smaller one. The second is taking the square root of a negative. And the third is dividing by zero. These are all things teachers told you that must not be done (end of the world or something)!