You just answered your own question. Back then, EVERYONE smoked. OK, not everyone, but such a large part of the population did and it was extremely socially acceptable. Even up into the 1980's cars were still built with ashtrays installed. I'm just grateful I grew up in a time when the health hazards of tobacco were known and the anti-tobacco movement, though in its infancy, had already begun to make smoking something to avoid. When I was in high school in the 80's, it was uncool to smoke. The only kids who smoked were the marginalized kids who desperately tried to act cool. But the rest of us laughed at them for smoking.

Of course what killed the desire to smoke for me was when I worked at my dad's shop, and the old guys in the town would come in to hang out and BS for a few hours while they smoked. All the cigarette smoke bothered me and I hated the way it smelled, so I knew I would never smoke when I got older. But even though smoking was on its way out, it was still pretty popular then and I didn't mind it quite as much. Now it's getting pretty rare that when I do smell someone smoking I can't stand the stench of it.