I recall exactly where I was when first heard of what'd later be called AIDS. Early 1980's and I was driving a Pontiac sunbird home from Church.
The radio man said a mysterious disease was killing homosexuals. It wouldn't stay mysterious for long.
That was more than twenty years ago, long before we learned that Rock Hudson was homosexual. Heck, back then we weren't even sure about Elton John, but most of us had our suspicions.
I mention that to note my membership in the last generation to reach sexual maturity before there was a fatal venereal disease. It'd be pretty difficult to imagine all the ways that makes me fundamentally different from people now in their 20's. But I'm certain it's there.
Not that the reality of AIDS has made people more careful, not that I can tell. The culture seems a lot more sexualized now than it did when I was young. The effect is much more subtle; it's a kind of fatalism present that must be accepted generally and denied specifically.
I don't recall a moment I learned about Crack or Meth. I remember Richard Pryor catching himself on fire, but with the instant zombie plague awareness slowly came to me I guess. First came the awareness there was something cheaper and more powerful than powdered cocaine hitting urban areas.
And then the hillbillys got into the act with Meth. I'm not the first to observe how much Meth manufacture/distribution resembles the moonshine biz. But it has changed our culture a lot, the convenience of the whole thing.
We were a much different culture overall, back when getting high on illegal drugs was more inconvenient. Oh, I'm certain that drug users would protest how it's still pretty damned inconvenient.
But to me it looks convenient. That's changed the culture by drawing more people in. Instant zombies are no longer an easily identified subset of the population.
Nope, I'm not pulling a 'back in my day' rant here. Just observing those are two ways I've seen the culture fundamentally changed while I was knocking around a few decades. Impossible to say what other changes are just around the corner.
Don't spend a lot of time thinking on stuff that you'll never figure out. There's no profit in it. Try to steer towards thinking about what's unchanging among these shifting sands.