Smoking is not as addictive as you think.
I want to clarify this statement by several instances:
1. Do you have experience that during a long exam, say 3 hours, you never have the desire of smoking?
2. Do you often wake up in the mid-night by the withdrawal symptoms?
See? The withdrawal symptom is not strong at all. If you forget the thing "smoking" in a long period, due to whatever reason, you will not be suffering. Suffering emerges only when you realize that you need to smoke and you can get some cigarettes without much difficulty, say from your pocket or a nearby gas station.
So physically, there is no such thing called "withdrawal symptom", or not as strong as you think, it only comes above the water when you realize it, and tell yourself the "withdrawal symptom" is coming.