I have mate (well mate's brother) who started smoking in his late 20s, because he thought it would make him look cool. I'm serious. He was a guitarist in a poor original material pub band and wanted to put the cigarette in his headstock. This was in the early 2000s, a few years before the smoking ban.
I have another mate who only smokes when he drinks. He smokes them like cigars though and doesn't inhale. I don't get that either. Again, he was in his 30s before he started doing that. He lives in Santa Monica at the minute and can't smoke within 20ft of a door or open window on a public building.
I honestly can't understand anyone starting to smoke at all once they've left school. By that time you should have more sense.