Once was for 7 days on a bet and I won 7 dinners. 2nd was with a patch and gum. The patch gave me a rash and the gum made me vomit so that lasted a few days. 3rd was for a month.
I did all 3 cold turkey, predetermined but at the end finishing a pack. Yup, that was the last. In those 6 months, I never even took a puff.
First time at the 6 month mark - My Dad (stepdad, but really my Dad) had Colon cancer, on his death bed but at home. My brother and I would leave his bedside and go outside for a breather. Yeah, my brother was a smoker and I relapsed.
Second time at the 6 month mark - My best friend and I made a $1,000 bet who could quit the longest. Young, drunk, stupid, and surrounded by a lot of nekkid women, we had our waitress bring us a pack. With a smoke in each of our mouth's, we lit them with one match. I kept the pack and was gonna throw it out later.
Third time was the day of my daughter's birth. We did prenatal classes and all that jazz, but they never discussed C sections. Early on the doc brought it up and prepped her. I was so worried, I went out and bought a pack which I pretty much finished 4 hours later.