Smoking is more than a habit. It is an addiction. I began smoking at a very early age. Quitting was difficult, all four times, but I am smoke-free. Like any addiction, your body has to adjust if you have cut the fuel to the fire.
Some folks refuse to quit because they're afraid they'll gain weight.
Well, we are what we eat, so it's a good idea to keep track of your calorie intake when you give up smoking. At present, the Calgary Tobacco Reduction Action Coalition is making some noise about second-hand smoke hurting children. They're using those figures to try and initiate a bylaw to prohibit smoking in any public place where children are allowed. I'd say their chances are pretty slim at best, and that's a shame. I would like to see smoking banned in all restaurants unless they obtain a smoking license and clearly indicate it is a smoking facility.