If I had to guess, it's because a lot of us here found highschool to be a highly traumatising experience, and it comforts us to know that there were others that went through that hell.

Personally speaking, it took me more than 5 years after graduating before I could even start to believe that people actually liked me. Even today I can still see little emotional tics, learned behaviours, that I developed during that period, that I actively have to work against, as they will lead me into unsuitable responses today.