I think it is mindset.
If you are thinking you should give up, it will never work, you have to really want to give up.
My Grandfather started smoking when he was eleven. He smoked tins of Senior Service unfiltered.
In his early seventies, he was half way through a cigarette one day & decided he wasn't enjoying it anymore, so he stubbed it out & I never saw him smoke again.
He lived another twenty years.
For myself, I used to smoke cigars, cheroots & if I couldn't get them, French cigarettes.
I haven't smoked for thirty years, but my mindset is 'I haven't given up, I just don't want one.'