Salut!

Never had a puff of a cigarette in my life but both my parents used to smoke. My ma smoked 40 a day, and just like that, when we moved into the house we now live in, 20 or so years ago, she stopped. She's always said, "You'll never stop unless you want to." My dad stopped at the same time but then just took up smoking again about ten years ago. Then stopped again, just like that: no declarations or anything.

Difficult to generalise of course, as everyone's different, but I guess there's a tricky balance between wanting others to know and retaining some kind of personal privacy about it; perhaps that stems from the fact that smoking's still socially acceptable, and so the 'shame' you feel in continuing to smoke is self-punitive rather than something you can talk about.

Good luck at any rate!