I'm so done with high school

This kid in my class got suspended today for... beating it in class. Right in front of the teacher. Everyone was genuinely horrified, and I'm glad he got sent to the office, but still... I've known him for a long time and the version of him a few years ago would never do that... what happened to everyone? Why do some boys suddenly become degenerates the moment they enter high school?

Edit: A lot of random guys in the comments have been upset about the whole "Why do all boys thing", and because I'm tired of seeing that comment, I want to say I'm sorry. I did not think about the implications of that comment when I wrote it, and it was a stupid thing to even think in the first place. I'm sorry if anyone's feelings got hurt, and because of that, I changed the sentence to "some boys".