I smoked for 13 years (ages 14-27). I was so very hard. I used to do cocaine and marijuana too. Those were fairly easy to quit did it cold turkey. I think it's because they're a bit harder to get though.
I was at one point doing about a pack a day because I could smoke on the job. I said for a week to do half a pack. That lasted a month. Then 4 a day. Lasted about 2 weeks. Then one a day which lasted about a month. Finally, I just got the gum. And chewed a piece a day until I started going back and forth to regular gum. Then just regular gum.
Although, now I do chew gum a lot. My teeth look a lot nicer though and it's a lot cheaper.