The thing about smoking is that when you quit smoking you quit it every day. Imagine a light switch on the wall. You turn it off by quitting smoking and you can always go back at a desperate time for instance and turn it on. And some time later off again. Smoking your first cigarette implants that light switch on your mind and you can't make it go away. Since you know how it makes you feel good when the switch is on,…
In fact, being around smoke doesn't make me want to smoke again. It's just the opposite, even. The smell of tobacco actively repulses me now, and if anyone lights up near me I start to feel sick. It's become a truly vile smell for me.
The hard part for me was just getting the motivation to quit. Nothing could really get me to want to quit, and I tried switching to vaping multiple times only to go back to kreteks, because I didn't really care if it'd kill me since I didn't really want to live anyway. It wasn't until I decided I wanted to transition that I got serious about quitting, because nicotine + estrogen is a really dangerous combination, so I realized I needed to quit if I ever wanted to be happy with my body. I switched to vaping pretty much instantly, vaped for a grand total of two months, and then decided to take a break for a few days before I got bloodwork done... and a few days _after_ I got my blood drawn I realized I hadn't touched my mod at all since and didn't even miss it, so I gave it back to the friend I borrowed it from, and I've been nicotine-free since (aside from one time, a year later, when I had a single kretek at a club just to prove that I wasn't addicted anymore and could have just one and then stop).
For what it's worth, I was a pack-a-day smoker for several years before I quit, and I've been nicotine-free for seven and a half years now (six and a half if you count the single kretek I had at the club after I quit).