"Legitimately", when I do not have a cigarette/cigar/pipe/"j"/etc lit up and am not firing an atty, I am a "non-smoker". And based on that criteria, I have "smoked" for a very small portion on my life.
I had a friend that I sat down with to play some pitch at the local bar and noticed he did not light one up for quite a while. Soon though he asked to bum a smoke and I kindly gave him one which he really seemed to cherish. A while later he asked again and of course I gave him another. The third time he asked to bum one, I told him "they sell cigs up at the bar". He said "no, I quit"! I replied "you didn't quit smoking, you just quit buying". Ba da bing!