This is to do with chemical factors and also psychological as you can't have a smoke during an occasion you would usually light up. By explaining the nicotine 'trick' to smokers he found that it was possible to completely change their perspective with respect to smoking. Last but not the least, setting up wrong examples for your children. This is why many smokers believe that smoking is an appetite suppressant and relieves anxiety - because a nicotine pang feels so similar to a hunger pang or a pang of anxiety