I almost feel bad for you guys. You guys are gonna feel old a lot sooner than I did. The way I spoke was still relevant at least until I was 23ish and then slowly tapered off.
Just take solace in the fact that when you guys are all my age you're gonna cringe so fucking hard at the way you spoke you'll collapse into a black hole. It happens to all of us so it's probably better if you know less.
After I watched slang evolve multiple times across only a couple of generations, I stopped worrying about being in, and realized as a writer that slang older than the parental generation stays classy. Also, there's no correct way to use a living language. References might tell us what was the norm at the moment they were published, but they were obsolete before they were sold.
I may have to invent a dialect combining Newspeak and Nadsat and go extra crunchy.