Seriously, I smoked for 17 years and was quite a heavy smoker, 30-35 a day. I was 33 and my doctor said I looked like shit, smelled like shit and would be buried like shit if I didn't quit (he was great on diagnostics but a bit low on the caring side of his business). He convinced me that I had failed to quit before because I didn't remove the toxins from my body, primarily the tar. He said that the toxins are held in the body fat and that they slowly release into the blood stream, causing the craving.
So, I went on a "live food" diet (salads, lightly steamed vegetables, California type crap), bought some of the nicotine gum and started walking 1 mile in the morning and 1 mile in the night. I had the flu for about a week or two as my body detoxed. I really felt quite crap. But the craving for a cigarette died pretty quick.
I remember chewing eight of those nicorettes the first day and I cut them out day by day so that in day 10 that was it. I would chew them only when I got frantic for a cigarette. They didn't work like a cigarette but I would notice fifteen minutes later that I didn't need one anymore. So, more subtle.
Pretty soon I was running instead of walking (OK, sort of running). I lost weight from about 212 to 178 and I still weigh 180-182 most of the time while eating pretty normally unless my weight starts climbing. Then I just go back on the diet for a week or two about once or twice a year. I run half-marathons (not very fast) and I have never wanted a cigarette again. I also don't have the other extreme of hating the smell, smoking is just something I don't do.
I think the major thing is that you have to do the whole thing. Get the toxins out of your system and get more healthy. It was a self-reinforcing cycle for me. I feel better today, nearly twenty years later, and have more strength and vitality, than I did before I quit.