A few days ago, I pulled out that ancient meme format "yo dawg I heard you like [thing]" to a couple of my friends. Weird to think there are teenagers alive today who are younger than that dumb gag.
There is a great relief in realizing pop culture has moved on without you and you are rapidly descending into irrelevance.
I had to cover the first day of high school today for the news website I work for and I immediately felt old and irrelevant.
I still say whatever out-of-date slang I feel like, but I also stay at least tangent to new pop culture teaching teenagers.
“Rad” and “rules” are just part of my regular vocabulary. I use them without irony all the time. If I want to be ironic, that’s what “fucks” and “slaps” are for.
I still say "tight" way too much, but I think that's now more of a regionalism than outdated slang at this point.