What is the biggest impact on what got you smoking? Family, friends, peer preasure, advertising, what?
Curiosity. And rebellion, I suppose. I always wondered what smoking was like, and since everyone was so emphatic that I not smoke, I decided to start (teenage logic).
My friends. When I worked at the food court, my friends would get a 10 minute smoking break while at work and there was a lot of socializing that went on, I felt like I was missing out, so I started smoking.
Both of my parents were smokers too, so when they told me not to, I was like "Yeah right. "
Severe peer pressure. My freshman year of college, I didn’t react to the stress of finals very well (many other things were also going on, including the recent death of a very dear friend). One night, my friends told me they were out of better ideas to make me less stressed, and I was going to take the cigarette. After an hour, I realized they weren’t going to let me sleep until I gave in. So I did.
Job stress. I was a non-smoker for the longest time, never desired to smoke, never gave into or really had any peer pressure. Plus, smoking in Canada is an expensive habit.
But I recently moved overseas for work, the job is very stressful and I had no outlet to take the edge off except for smoking. Since I only drink socially and whereas in Canada I would happily smoke a joint to unwind I’m in a country with very strict drug laws and the availability of the herb is next to nill.
Smoking now relaxes me. I’ll quit when I’m finished my job here though.
Friends in high school, not a movie.
What acconav said. Rebellion mostly, and then I got stuck.
Oh, definitely the ads. “Winston Tastes Good, Like a Cigarette Should.” How could you NOT smoke after reading that?
Okay, seriously, in my case it was Adolescent Literature. EVERY cool protagonist in my teen reading smoked. James Bond. Holden Caulfield. Sherlock Holmes. Dean Moriarty. The Duc Jean des Esseintes. Sam Spade and Ned Beaumont. The guy in L’Etranger.
Not to mention all the beatniks and jazz musicians and Humphrey Bogart.
I started when I was 20 because of stress, I was travelling and alone so noone influenced my decision to smoke, but I have stopped smoking now. 
I thought it looked cool. I still think it looks cool (note I am not presently a smoker). I know it isn’t and nobody needs to tell me that, thanks. But I don’t think I’ll ever stop imagining it does.
I no longer smoke, but started at age 12.
Most of my friends were older and already smoking and I think I wanted to keep up with them. They never pressured me to smoke, but it was nice to have it as a common interest.
My father smoked and it was easy to get them.
Now none of my friends smoke and I quit seven months ago. When I go back to the Midwest, though, I notice that everyone still smokes. I think it was a “fit in with the crowd” reason for why I started AND why I quit.
Definately rebellion. I don’t remember much, if any, peer pressure to smoke when I was in high school. my friends were split about 50-50 between smokers and nons. Certainly not advertising, Cigarette ads are worthless. Well Except for those truth.com ads, they always make me feel like lighting up.
When I was 8 or 9 my family thought it was cute when my two grandfathers gave me Copenhagen. When I hit junior high I was informed that Copenhagen was not a thing a girl does and instead started stealing spare smokes out of my father’s pack.
Alcohol.
Most of my friends I had at 17 or 18 smoked, so I started smoking with them at parties. That segued into about 2.5 years of smoking. Now I’m back to very occasionally smoking while drinking.
No intention to smoke here, it just kind of happened. After starting my first job, a bunch of us went to the pub after work for a few drinks. One guy offered me a cigarette, and I just thought “What the hell, never tried it before, let’s see what it’s like.”
I thought I’d end up coughing and spluttering, but to my surprise, I actually enjoyed it. Been a full time smoker ever since.
What ruadh said goes for me as well. I think it looks cool. I also found that I enjoyed it. I’m not a “smoker” (at most I smoked a pack every 2-3 weeks, now one pack will last months), but I will do it when I drink.
I quit smoking over a decade ago, but I started smoking at age 14. I did it because I had a crush on a boy who smoked, but I was too shy to strike up a conversation. I figured that if I took up smoking (his brand), I could bum a cigarette from him and start to talk to him that way.
For the record, it worked, but the addiction to cigarettes lasted a lot longer than the addiction to the boy.
I wanted a prop.
Didn’t realize it would turn into a crutch.
Peer group pressure, certainly. And the ruthlessly efficient promotional campaign run by the ice-cream van that parked just outside the school grounds. You could by cigarettes individually, and many did. I suspect that this doesn’t happen so much these days.