I quit my three pack a day habit in 1990, after about 30 years of smoking. It was easy, but I don't recommend the method.
I hurt my foot (perhaps it was my first flareup of gout), and couldn't walk enough to get to the store to buy cigarettes when I ran out...which wasn't long with my habit. The pain in my foot kept me from thinking about the pain of withdrawal, and by the time I could walk again, the habit was broken. About a month later, I found a pack under the seat of my car, and smoked them, but didn't get any great pleasure from it. About a month after that, I bought a pack, but found I disliked smoking. That was the last. I haven't had to fight any urges to smoke. I did gain about 30 pounds, though.
One sort of weird thing: Even though I've had no urges to smoke while awake, I'd often dream about smoking, but in my dreams I'd realize that it was only a dream, and that I wasn't really backsliding to my smoking condition. Ex-smokers often complain about the smell of other people's smoke, but it never has bothered me...I actually find the smell of cigarette smoke pleasant, but it doesn't make me want to start up again.