15 year smoker, 1/3 pack a day... quit cold turkey two years ago. still have an occasional casual social puff, but definitely never going back to buying cartons and always carrying around a lighter or matches. the cycling has improved as a result but i can only imagine how much more fit i would have been with smoke free lungs... although i hear the body is pretty amazing at self repairing itself so long as too much damage has not been done.