I was in a play and my character smoked. I had never smoked before then and fell in love with cloves. (I hated the smell of regular cigarettes.) I smoked off and on for two years. Never more than three or four a day, mainly socially on weekends when drinking. I was dx'ed a couple of years after that.
I don't know if you are aware, but the American College of Gastroenterology is being held in Philly right now. Last night I went to a symposia that included some hard data on smoking and its link to surgery. That's right, if you smoke your chances are much greater than that of a nonsmoker to need surgery. But don't worry, if you quit those chances (over time) will go back to that of a nonsmoker.
I'm not judging or trying to tell anyone what to do. But after hearing the data (and knowing that smoking is generally bad for health) I will never pick them up again.