Well, yeah, that's the thing. It seems that with a hard drug, you can lock yourself away for a couple weeks (go out to the cabin, out on a boat, to a rehab clinic, a friend's out in the country). The experience is crap; enough for lots of people not to want to go back in once its over. Sometimes dramatic enough to change a person outright.
With cigarettes, I've done that several times and always came right back (the withdrawal symptoms are hardly noticeable, except for the raging caveman/toddler being in your stream of consciousness that wants you to give in... but that withdrawal symptom lasts for the rest of your life, albeit with diminishing effect over time). There's no character building from the withdrawal process; no tearing down and rebuilding of the psych.
To quit, I had to basically do an extensive psychological self-deprogramming (with the help of Allen Carr's mysterious wonder, "The Easy Method..."). I remember even thinking some of the neuro/psych in it was hokey, but I read on and it worked. Society accepts it, companies advertise it, the government banks off it, and the drug itself rewires your whole reward system for the rest of your life. At this point, it only counts against it that the physical withdrawal symptoms are trivial. Makes it easier to give into one of the millions of constant barrages of cravings that come in after quitting.
It's such a trivial little thing.. one cigarette won't hurt... maybe just a puff first, maybe that will be enough... maybe I'll just walk by somebody smoking and take a deep breath...