I was a complete slacker in high school, but I was probably still a nerd. I was a bit of a troublemaker, but in the end I still loved classic literature, Lord of the Rings, and the internet and didn't care at all about sports or fashion.
Even so, never studied for the SAT, scraped by with only taking exams in my classes (and never turning in homework or, uh, attending, though somehow I still got Bs), and spent most afternoons in detention. I wasn't concerned with my grades at all and was thinking about dropping out of school to become a motorcycle mechanic.
It was a 180 degree turn around when I was in college, for sure.