I've been a 3+ pack a day smoker for 35+ years. Haven't had a smoke for 45 hours.
My stepfather smoked for 20 yrs (unfiltered Lucky Strikes). He was in the hospital for “jaundice,” and the doctor told him the news that it had just been determined smoking would cause cancer. He threw an almost full carton in the trash. On his way home, he bought two “store boxes” of Dentyme gum (he hated it). Whenever he craved a cigarette, he would take a Dentyne instead. He never smoked again and never bought any more Dentyne.