Why do people start smoking?

I’ve been thinking about that for a while, and I can’t some up with a good answer. Some friends say that they do it because everyone else is doing it, but I don’t smoke. Same goes for snuff (yeah, that’s what the dictionary says :D), which has become the new trend here in Sweden. Usually only hillbillys and such takes snuff, now it’s cool I guess. Is that the only reason to smoke? I can honestly not think of any other reason.

This is not a hate-thing about smokers in general, I know a lot of smokers. Just don’t blow smoke in my face, it makes my mom ask me questions.