That is both a logical and reasonable question.
And you may have asked it many times, 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. When networks are fully established, we often call them habits; just like the one in the picture! And that gives it a head start on all of the other methods.
But there's more to it than that because from an observational perspective, one thing points to the longevity of hypnosis, is, the way it retrains the brain to work differently. Once a more empowering and beneficial mindset is developed, there's really 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 a mere fact of memory. The old emotional/psychological beliefs relating to survival, acceptance and or approval no longer rely on smoking as a supportive crutch. 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. They often say, I just took one and I became hooked; again! In reality, this is most often 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'd be compelled to go to work and forget your day off. Perhaps doing the same every time you have a day off from now on too? 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'll be instrumental in quitting too. And after that, it's just as likely to be instrumental in staying smoke-free! In the end, it's a choice and one that is backed up by powerful benefits in staying healthy. Smoking is a two-way habit, one where you pay upfront and then pay again later!
Make that decision to quit today and I will help you achieve that!