I generally explain it like this:
There were good reasons to stop smoking, but having good reasons did not make me stop smoking. Finding something that gave me everything (and more) that I wanted from smoking, and which was preferable to smoking in every respect - that got me to stop smoking, completely and instantly. I've not had a cigarette, nor any desire for one, since the day I bought my first cig-alike, ten months ago and counting.
Now, if something comes along that offers me everything that vaping gives me, and which is preferable to vaping in every respect, then I'll be happy to consider it. Frankly, I do not expect that kind of miracle to occur twice in one lifetime. I may reduce my nic strength at some point, either to make my supplies of nic base last longer, or because I feel I'm getting too much nic at my present level. Otherwise, it isn't going to happen.
Also, remember the part about there being good reasons to stop smoking? Well, there *aren't any good reasons* to stop vaping!