I was one of those people and consider myself very lucky. My first puff was at 9 but I didn't start regularly smoking until I was 14. In a third-world country where the laws, if they even existed, were hardly enforced, it was easy to buy smokes as a minor. It was normal, even.

I smoked through my teens and 20s and into my 30s. Then one day, I decided to quit because I knew it wasn't healthy and I had seen pictures of smokers' lungs. I didn't experience any "jonesing" and didn't need to replace the habit with gum or patches or anything. It might have helped that I worked from home at the time and was addicted to video games, so I was very motivated to stay at home. I turn 50 this year and haven't smoked since.