That is both a logical and reasonable question.
And I'll bet you have asked it many times and in many different circumstances?
All things being equal there is no less a reason for it not to last than by any other method, e.g. patches, gum or just plain will power. However, hypnosis is somewhat different than any other method because it works by reorganising neural networks in the brain and when networks are fully established, we often call them habits; just like the one in the picture above! And that gives it a head start on all of the other methods.
But there is actually more to it than that because from an observational perspective, the thing that really points to the longevity of hypnosis, above all other methods, is the way in which it retrains the mind to work differently. Once a more empowering and beneficial mindset is developed, there really is no reason or desire to smoke again; ever!
The brain and mind work by association and cell/gene expression, simply the result of a combination of internal and external stimuli. This is merely a fact of memory. The old emotional/psychological beliefs relating to survival, acceptance and or approval no longer rely on smoking as a supportive crutch. And because there is no longer any internal or external logic to drive the behaviour, quitting is painless, rewarding and makes us feel good about ourselves.
That said, many ex-smokers make the mistake of one day accepting a cigarette from a friend or a stranger. Clients often say, I just took one and I became hooked; again. In reality, this is just a one-off that was given a powerful self-statement. One could equally say that was silly, I won’t do that again!
It’s like those times when you have a day off work and want to go somewhere and mysteriously find yourself driving to the office! Using the same logic, you would be compelled to go straight to work and forget your day off; perhaps even doing the same every time you have a day off from now on! You’re hooked on work; right?. The same illogical rationale equally applies to cigarette smoking. Just accept that it was a mistake and choose to let it go and move on.
Your mind was instrumental starting to smoke and it will be instrumental in quitting. And after that, it's just as likely to be instrumental in maintaining that. Staying smoke-free is by choice and backed up by powerful benefits in staying healthy. Smoking is a behaviour (habit) where you pay up front and then pay again later!
Make that decision to quit today and I will help you achieve that!