You’re just getting old.

Yeah the same is true for me and you and everyone else. But the rate of change of lingo has increased because the power that used to belong to only people with direct access to mass media now belongs to anyone who has or had a "viral" moment.

Sure back then it probably took a few years to spread within the anglosphere, but OTOH there was also much more dialectic variability in language across regions so it’s not like there was less going on, it was just more fragmented.

That's exactly the point. Of course language isn't static and wasn't static ever, but the ability for lingo to spread and become mainstream has increased with the ability to reach new audiences provided by new forms of mass media (termed as social media).