Maybe it's just me, I don't know, but I've been smoking probably an average of 10 cigarettes per day from age 14 (so that's 5 years of smoking) and show minimal signs of addiction. Periods of that I've smoked 20/day consistently and periods less but I'd guess that I've probably smoked an avg of 10/day.
I can go a day without a cigarette, it's not a massive problem for me. I go a day without a cigarette on a semi-regular basis (probably once/month) and although I'm agitated and craving the feelings really aren't that strong and are fairly easily ignored. Whereas some people seem to smoke for like half a year and are suddenly really addicted..
Why don't I quit you ask? Well I have cut down massively recentley but I don't think I could quit very easily for the simple fact that I go out on the weekends and most people, certainly all of my friends, smoke. Plus the fact that cigarettes are for whatever reason awesome when drunk doesn't help.
When I smoked, I wouldnt smoke at work and would work sometimes 12 hours a day. Quitting still sucked.