I have two stories. First story, a friend visited our house and was vaping instead of smoking. Our first exposure to the vaping thing. I tried it, and his juice was an apple flavor that didn't appeal to me, but I was intrigued with this new tech! A couple of months later it was Christmas, so I said, hey, let's get a couple of these things and just see how it goes. So we picked up a couple of ego Ts and CE4s plus some small bottles of tobacco flavored e liquid for a rather silly-high price at a B&M. We didn't actually use them until New Years (hey! did I spy a resolution?!), and even then we weren't committed to vaping only. I figured we'd go with no more smoking in the house and use the e cigs inside. But I didn't smoke again after that, at all. And it was easy. UNTIL [ominous music here] ...
Story 2, after about a year of not smoking at all, I had a stress issue, and picked up a cigarette. Such a very bad idea. It tasted absolutely horrible. Yet I persisted. And yes, started smoking again. After a couple of months of smoking with all my vape stuff staring at me accusingly, I shoved it all into a drawer out of sight, and kept smoking. Then one day I was out of cigarettes, and like so many other times before, I said to myself, "you could just not buy any more. You could just open that drawer and start vaping again instead." And this time I did. Why that day, and not any of the days before? I don't know. It was a day like any other day. But I knew what it was like not to smoke, and I was sick, sick, sick of smoking again, even though I wasn't "sick."
It wasn't as easy totally quitting the cigarettes the second time. I wasn't dual using, but I would have two or three a week at first -- unlike the first time when I just cold quit (without even really intending to). I took out my easiest no-problem stuff, the Nautilus minis and iSticks, bought whatever fancy expensive e liquid I wanted as an incentive and got down to not smoking again. And it's been ... about a year? Again not smoking.
I think the first time, I was so enamored with the shiny new technology and TOTALLY AMAZED that I could just vape and not need a cigarette. The second time it was not a brand new amazing thing, so took more willpower to cut the cigarettes. Both times I did it for my health, and because it makes everything disgusting. I wish I had never picked up a cigarette again after successfully quitting, but I'm quit again

and wiser about the lingering temptation of just-one, just-for-today, just-while-I'm-feeling-so-upset, just-for-now. I naively thought I was safe from that, but I wasn't, and now I know: in the same way that "trust but verify" is a useful maxim in life, so is (for ex-smokers) "trust (in your non-smoking), but fortify (keep your guard up)." I won't take quitting for granted again.