Im a smoker in my mid 20's, I staterted when I was 13. So safe to say I knew the risks, yet I still started. I think there is more than one reason I started. First I grew up around it, so it was a normal thing for me, second all my friends were trying it or already doing it, and last to rebel. Clearly not the best reasons to start, not that there is a good reason too. Now 11 years after I started I want nothing more than to quite. Ironically most of the friends I had at 13 when I started smoking have since quite.

Good topic. Thanks!