But my experience is that people who didn't grow up using drugs as teenagers are somewhat unlikely to start using them as they approach 40, particularly in conservate societies, and were even less so in 1983.
There was a story on NPR recently about the ages at which people stop experimenting with new things (music, food, and piercings were mentioned), and it supports your observations.
On the other hand, sometimes I wonder if my friends' parents weren't a lot wilder than I used to think.
I bet some of them actually had sex, for instance.
(Not mine, though, of course.
)