I haven't touched a cigarette in, oh, 4yrs or so. It was definitely the hardest thing to do in my life. Harder than leaving the witnesses or divorce. I accepted that I will always be a smoker, I just choose not to. It gave me power, rather than say, I am giving up, which sounds powerless. It took a couple of go's and then something just shifted. I lost the desire....
Talesin nailed it. It was so hard because cigarettes were always there, in any situation, when humans were unreliable. I finally became responsible for myself and excepted myself, "good" and "bad"