It'll be 5 years for me this coming Feb 17th. But my story is kind of unique, I was flat on my back with a very nasty case of the flue. I couldn't get out of bed for over a week. At first I was craving a cigarette but I had such a fever and nausea that I couldn't even get out of bed. I kept thinking about smoking so much that I guess I soon came to equate feeling sick with smoking and the thought of having a cigarette made me nauseous. That feeling lasted long after I was back on my feet again and I haven't had a cigarette since.
Never underestimate the powers of negative reinforcement.
Mark
Good luck.