I had a dream last night in which I* was a chain smoker. I could even taste the cigarettes and was enjoying them, even though I have never smoked before in my life and would sooner ingest an overdose of rat poison than a single breath of cigarette smoke (directly). I also gag every time I accidentally inhale that filth, in real life.
In it, I was trying to quit, because I was a smoker against my own will and because I had to keep it a secret from my family. But I couldn't help myself.