Many, many years ago, I smoked a pack and a half per day. Because I could. There were no restrictions anywhere. I remember visiting people in the hospital and having cigarettes with them in their room (even if it was shared by a non-smoker). Then, thankfully, we passed laws that outlawed smoking indoors. I never smoked in my own home, because I couldn't stand the smell in my curtains, carpets and furniture fabric. (I know, pretty sick, huh? I'll ruin my employer's place or a public hospital or restaurant, but keep it away from my home!)
So practically overnight, I had 8 or more hours per day that I was unable to light up. I went from 30 a day to 10-15 a day. I went from smoking anytime/anywhere, to carefully planning out when I could have my next smoke. I remember that awful feeling inside me when a planned cigarette break couldn't happen for some reason. And I remember the absolute glee I felt when an opportunity to smoke happened when I wasn't expecting it. That became the new norm for the last 30 years.
After 10 weeks, I've lost the habit of planning out my day of smoke breaks. But every time one of those unexpected opportunities arise, I still find myself looking for my pack. That old habit just won't die. Luckily, I'm able to laugh it off and move on.