Smoked for years, never tried to stop as didn’t believe I could – and didn’t really want to anyway.
Smoked 40 (probably counterfeit) Marlboro red one night and just decided to stop the next morning.
I was climbing the walls for 24 hours, felt wretched for about three days – then the withdrawl symptoms tailed off so much that the sense of achievement I was feeling far outweighed any remaining desire for a fag.
That was about seven years ago and still haven’t had one.