Had an English prof in college who smokes Wings, and she could find WWii packs and would smoke them ... and that was in the mid sixties!
Nicotine addiction is one of the worst.
I was a chain-smoker and a stress-smoker. There was a time (read many years) when I smoked FIVE PACKS a day.
It took me six years or so just to reduce that to one pack a day.