You missed the point...So? Who cares? If you're stupid enough to make massive mistakes at age 17 then chances are you'd make them at 21 as well.
I was on schoolies when i was 17 and had no problems at all. If you're thick enough to do hard drugs in an area swarming with police, or have sex with multiple random partners then you'll get what's coming to you. It's not rocket science, and any 17 year old should understand that.