There's your problem...
Not to further derail the thread, but I'll pitch by two cents anyways. I went to three different high-schools in Canada, graduated last year, and not that many people smoked cigarettes at any of the schools. Comparatively of course. There was always the two distinct groups of people, the "smokers" who stood around outside between, after, and before classes smoking. And then all the non-smokers who, rather obviously, didn't smoke. There was also a rather obvious correlation between the success/grades of the smokers and non-smokers. I never had anyone who smoked in any of the AP or "academic" (ridiculously broken system, but that's another discussion) classes I was in. The smokers were always in the levels below, always had more issues with attendance , and stuff like that. But that's more specific personal qualities (or lack thereof) than a direct influence of cigarettes. If someone of that group didn't smoke, chances are they'd start, as it's been said before in this thread, just to "fit in".
But, on the current topic of marijuana and other "drugs", they're completely different; at least in my experiences. It really changes depending on where you are, each city and school kind of all follow a general similar opinion on that stuff. Here in Ottawa, pot's not nearly as popular as it is in other cities. In my hometown (Thunder Bay) you'd be hard pressed to find a highschool student who hasn't tried it at least once. Vancouver was similar, but I wasn't there for that long so meh. And it's not just the same "smokers" who slack off in school and are considered "failures of society", the kids who have 90+ averages and all the "nerds" would partake as well. Not to get into the whole marijuana is bad for you debate (which it probably isn't), but it's clearly not nearly as life shortening as cigarettes. Personally, I'm in the same boat as Raguvian. I don't take anything to extremes, but I'm not a complete conservatist either. I've had great times while "under the influence" of certain substances, didn't make me change my outlook on life, but it also didn't make me a complete failure either. It depends on what you're views are, I don't discount anything without trying (within reason of course). If Cifani chooses to do so, then let him wallow in blissful ignorance and move on.
I'm in university for Computer Systems Engineering, I've worked for the Government and in private industry, and hardly ever use what I've "learned" in school... But again, that's another discussion.