Contrary to popular belief, Connor didn't skip class in order to get high in some reclusive part of town, less so in the back of school; he actually didn't smoke at all, but he guessed the smell of ash that clung to him could confuse anyone that got close to him. If anyone bothered to follow him when he skipped, they would find out why exactly he smelled like ash, and Connor would have to threaten them into secrecy, because his secret was a bit of a big one. Thus why he doesn't mind being the school's psycho, not as long as it keeps people away, he can't really risk someone finding out; of course, someone does.