It took me 42 years to quit. The only way I could succeed was when there was no pressure for the fist week. I still crave a cig but do not mind other folks smoking. But, my muscle memory still wants my right hand to do something in similar situations. Scratch my head or pick my nose, or clean an ear...those kind of things.
"An addiction is a personal thing where you quit and the reward yourself later by doing again!"
~Richard