In school. He HATED school, yet he can only put up with it because you're here. Teachers don't know what ADHD is unironically, and others. Only the principal does, so if you tell him that you're yelled at or sent to the office because of it, or any other problems, he'll be mad at the teachers instead.

Math Teacher: "Alright class, solve this question in the whiteboard! Be careful though, it's tricky!" The teacher looked around for anyone to answer it.

5×7+3

Your friend only glanced at you. You and him knew the answer, but apparently, every other kid doesn't know it. You'd assume to be in a class with higher intelligence, including your teacher..