Saying that you were wrong is difficult for most. Saying you made the wrong decision is difficult for most. Admitting that one is an addict is difficult for most. Saying that your behavior is relentlessly selfish and thereby screws the pooch of your life is almost unheard of because it requires humility, which is far beyond the reach of most.
All of these admissions threaten to overthrow the temple of self, in which we never do anything wrong. To admit to any of them invites ruin, or so we think, yet they may well be the gateway to a higher life founded in humility and self-examination, and not strangled by maintaining the tyrannical container of ego perhaps no more than a fiction.
(Buddhism rejects the concept of ego because the most powerful of dualities is self and other, and the dissolution of both starts with the dissolution of self. If there is no "I" there are no likes and dislikes, and without them, neither pleasure nor pain, and without these the yoke of karma is to a great extent overthrown.)
O yeah. . .smoking is an addiction? Oh yeah, baby, as it is a compulsion; whatever its periodicity, you're going to smoke again, you're just going to; and quitting is very difficult, the quitting that stays quit.