I've been a 3+ pack a day smoker for 35+ years. Haven't had a smoke for 45 hours.

I dunno. A guy I've worked with for years (he followed me from my last job to this one.. well, ok, I pulled him along with me , lol) has never smoked. There were times in our last place of employment he would have to ride with me for a couple hours, and it never bothered him that I smoked.. he liked the smell, lol.
My dad smoked around me when I was a kid and it never bothered me. But after just under about 2 years after I quit, I can’t stand it at all. When my wife and I go on a cruise, I have to hold my breath to walk through the casino. Then I smell the stink on my cloth for hours after.

I guess some people would never get to that point, but I’ve heard many other quitters say the same thing.