Yep, its 4 years today.
Not one puff since 12th Sept 2008. For me, and this always causes disagreements on here, one puff and you're not quit and so the counters reset. Anything else and you're in danger of thinking that an occasional puff is ok, which leads on to more and more and then before you know it you are a smoker again.
In short you are only quit since you last smoked.
This is only my opinion and I don't want anyone to think I'm trying to preach or belittle.
I'm happy to be still here because this has been a year of massive stress in my life both personal an professional. Life has changed a lot but one thing is the same.
I don't smoke.