I'm a teenager. And I think it's completely stereotypical of you to say that every teen experiences sex, drugs, and alcohol.
I've mentioned before that my father is an alcoholic, and I take that issue very seriously. I'm quite strongly against the whole drinking thing, and I don't know anyone under legal age who's done it.
You say that you know people who have done sex and drugs, and I would question how different your culture is from American culture. It's certainly more common in intercity areas like Chicago or New York, but in smaller cities, like where I live, and where Malcolm presumably lives, underage sex and illegal drugs are the exception rather than the rule.
Laws are pretty harsh for that sort of thing here, and if people do it, a lot of times, they spend the better part of their lives in jail. In Wisconsin, having sex with a minor is considered rape because anyone under the age of 18 cannot legally give permission to; and the alcohol is also almost-completely-zero before teh age of 21 here. I say almost because there is a loophole in the law (Wisconsin law, anyway) that minors can have a drink if they're parents are present; like a beer at a bar, or some wine at a Christmas party. But other than that, alchohol before age 21 is punished pretty severely. Same thing with drugs.