Started cycling at 27, started lifting at 14. IMO the guys who cycle early are the same ones who rarely keep any of their gains. Hell I've been at it for 17 years now and am still learning how my body reacts to certain diets / traning.
Unless you're competing, I don't know why anyone would be doing roids at 20 years old. Any dude at that age can run a mile a day and hit the gym 3x a week and be ripped, and still have plenty of chances to go out and drink his ass off every weekend.
On the other hand, alot of people experiment with "other" drugs in college, so I guess if I could go back I'd probably take the needle over any of those "others".