I believe that the wanting tells a silent story usually of the form "this experience will be worthwhile & net-positive." But that is of course just that, a story, and in reality things like smoking aren't worthwhile, and are net-negative.

In his book about quitting, Allen Carr posits something very similar -- those who fail to quit smoking implicitly believe there is /some/ value provided by the smoke, despite the health costs. For example, one might believe the story "this smoke is getting me through the day, although it's literally going to kill me."

Carr suggests once you truly accept smoking adds nothing to your life, and only takes away from your experience, only then does the motivation to quit rise high enough to boost your willpower to actually cease smoking. It's an interesting idea and something I've found to be true in my own life.