Do you you have a child who throws temper tantrums? Or have you ever done it yourself? It’s like that. “Craving” a cigarette is not really like the physical substance dependence issue experienced by a junkie craving a fix, or an alcoholic craving alcohol. In those cases, craving refers to a loss of mental and physical control, possibly even a serious medical problem. With cigarette cravings, smokers are not experiencing a significant chemical withdrawal effect, they don’t need medical attention, it’s really a behavioral matter.
If you say, “I’m craving pizza for dinner” there’s a good chance you’re just communicating that you’ve already decided to do that and you’re really looking forward to it. Smokers get a lot of behavioral reinforcement and repetition from saying “I really really want one!” and “I’m really looking forward to it!” Then they always have one right away, or as soon as possible — immediately giving the brain a dose of reinforcing drug effect in return for simply saying “ I want it!” The more you reinforce (reward) and rehearse that cognitive / behavioral response, the more powerful it gets.
Imagine if you gave your child a piece of delicious candy every time s/he said, “I really really want candy!” Do this about 20 times a day for X years. Then, one day you look in the jar and realize you’ve run out of candy, or you suddenly decide to stop allowing it. Imagine that child’s response to this new information, and you’ll understand the true nature of a smoker’s “craving.”