I have never smoked, but I'm old enough to have grown up and spent many years, decades, in an environment where just about everyone smoked and thought nothing of it. Most people literally did not know what a clean, fresh, non-smoking environment was like. Oddly enough, the smell of stale smoke seemed "normal" just about everywhere and even in the remote outdoors there would be someone with you who was smoking. So, even non-smokers often did not have truly fresh air to appreciate. As fewer people smoked and some placed became smoke-free, there was a whole new awareness of what fresh air really was. In that respect, many who still smoke have not discovered the difference. A non-smoker in a fresh air environment can smell someone smoking a hundred feet away. I suspect a smoker may not notice.
My husband totally gets the full understanding of what was said here. He grew up with chain smokers that never cracked a window in the house nor in the car. He began smoking at age 13, in the house and his parents did not care. So, here you have 3 heavy smokers in a house about 1,000sq ft. I don't smoke. You see where this is going.
He agreed to do his smoking outside, but in reality, the smoke just follows him when he walks inside. It even follows him up the stairs and down the hall to the bedroom for that last nightly smoke. My nickname for him was Pigpen from Charlie Brown, because he always had a cloud around him.
For the most part, the air in the house was fresh, but his clothes smelled just awful. His smoking hand was nasty too and when he would hold my hand, the smell was transfered. When he would go to his parents house, he claimed he could not smell anything wrong. It was just normal air to him. When he would come back home, I would wash his clothes 3 cycles to remove the smell and the suitcase, used only for those visits, would go in the garage wrapped in a plastic garbage bag. He never noticed a problem. So, right there proves just because a smoker lives in a house that has fresh smoke free air, they don't notice a difference as long as they continue smoking.
My husband would sit in amazement that I could smell smoke from a mile away. We could sit at a redlight with the windows rolled up and I would say "The car ahead has a smoker, because smoke is coming through the vent." Sure enough, when we pull up to pass, there was a smoker in that car. Perfumes always bothered me. He never noticed the strength. He really thought I was crazy when I said a strong odor of smoke or perfume gave me a headache.
Well, he stopped smoking a year ago. 30 years of smoking. He never realized how bad he smelled until a few months after stopping, we ran into an old friend in the store. I kept moving and my husband came quickly behind me. he said "That guy reeked and I had to get away so I could breathe". Then he said "Did I smell like THAT

? I said Yes. He now smells the smoke and the strong perfumes. Something he never did before. He is sensitive to sgtrong smelling fabric softener on the laundry. He now sees the difference. It was not something he could see by just living in a smoke free house. He had to be smoke free himself.