I'm sorry but I really hate the concept of "if you take a puff ever you will relapse into a full fledge smoker"...I see a lot of it and I am not advocating slips or anything, but I really think it just lays more guilt than necessary on people who mess up. It gives the impression that if you ever screw up...even 10 years after you have been quit..you are basically screwed once again.
Hopefully people never WANT to smoke again after they quit, get past the craves, learn to enjoy life w/o cigs ect. But even a slip doesn't have to turn your into a pack a day smoker again unless you let it. We have some control over this addiction, otherwise we would not be able to quit.
However, the whole point is, we can't turn it on and off at will.