As quitting smoking is considered by some to be more difficult than kicking a heroin addiction, you can proudly say you have the will power to achieve whatever you set your mind to, even in the unfortunate event that you resume the habit (but have faith that you won't)...aside from all the health benefits, that's probably the most important lesson to be learned.

It's truly an accomplishment that you can be proud of. You learn so much about yourself when you surmount a seemingly insurmountable obstacle.