I started at 19, it was totally peer pressure, everybody at work did it on breaks and I wanted to fit in. quit after I left that job and started again when i studied in France for 6 weeks, basically had nothing to do at night and would sit in bars or cafes and smoke and talk......smoked on and off for a while, but started again regularly about 3 years ago.....I smoke about a half a pack a day, mostly in my car