I started smoking in university, and where I'm from a very high percentage of university students smoke (usually roll-your-own cigarettes, though).
I can remember the first time I had a puff of a cigarette, and I was quite drunk at the time. The thing about smoking while drinking is that, at least at the start, a cigarette seems to make you twice as drunk as you were before, while also making you feel really good.
Of course before this I had smoked weed a bunch of times, and here that is usually mixed with tobacco in a joint, so I was used to it at least in that aspect.
But most people here who smoke weed and not cigarettes are quite able to handle the occasional tobacco in a joint without making a cigarette habit out of it.
Anyway, basically it just started out as something that I would do while out drinking. I would get drunk with my roommates, and occasionally have a puff or two from a cigarette in that state. Eventually I would have a whole roll-up to myself. Eventually I started buying my own tobacco to use with my own weed, and at times I would occasionally have a pure tobacco roll-up with no weed, just for the nice feeling.
For a lot of people, it generally starts out with the connection to drinking. Drinking and smoking are very conducive to each other, and it's how many many people get started.
I don't think I need to go into the details of how alcohol affects your judgement.
How my addiction came about was a slower process. At one point for whatever reason I decided to have a cigarette in the morning just as I was walking to my college, and by god did it feel great. At this point I was still convinced in the back of my mind that I had it under control, and could quit whenever I wanted.
The tradition of a morning cigarette turned into a necessity. Within about 6 months, I had an awful nervous feeling in my arms and stomach until I had the first cigarette of the day, and once it gets to that point, you're screwed.
I was young and foolish, I was drinking, I was doing it with my friends, I was getting social satisfaction from it. I enjoyed the ritual of making the trek to the smoking area with a friend or two for a nice chat while everyone else was inside.
I was smoking up until early August this year. I'm not a drinker at all anymore, and it's always been completely clear to me the health risks of smoking cigarettes, but the excuses still pile up: stress at work, stress at home, no time, trying to find as much enjoyment from my free time as I can, etc.
I switched to an e-cigarette (I hate that term, by the way, much prefer vaporizer) then in August, and the difference has been night and day. I never had another cigarette after that day, and to be honest, I despise them now. I've never had a craving for one and the smell of the smoke disgusts me now like it never did before when I was a smoker.
My cravings have gone down as well. I no longer feel that nervous feeling when I wake up in the morning. My nicotine requirements have gone way down. I'll be moving to a lower nicotine % juice when my current bottle runs out. My blood pressure is great, I can run again, my circulation is better and I don't cough up gunk.
I still have no full intention of quitting. Nicotine for me, like caffeine for some, is an aid to my work pattern. Walking down to the curb for a cigarette or leaning back for a few puffs from my vaporizer are the things that get my mind past a difficult bug or coding problem.