I have a fun experience with the Alan Carr book. The first time I read it, I was laughing the whole way through thinking about how much it was written like straight-up brainwashing propaganda, but I had committed to a friend to reading it all the way through. I got to the end where the final bit is something like "now just say out loud 'I am a non-smoker and when I wake up tomorrow I will never have a cigarette again'". I chuckled, thought it was ridiculous, and the next morning I woke up and didn't have a smoke. That lasted about 2 years until I got extremely drunk one night after a rough breakup, had smoked the whole night, and was pretty much instantly hooked again.

Ten years later I went through the exercise again, but sadly it didn't work nearly as well as it had the first time around.