Except it can't be fandom, because I'm only on the outskirts of it, so it is...the internet keeps you young? Or being immature and not having kids? Too much Tosh.2.0 and The Soup? Or something?
One of my cousins posted a list of slang terms on her FB that her two kids (both under ten) use, and a lot of her friends answered with other slang terms they hear their kids using that they didn't understand...and not only did I know most of them, but I use some, and could have told her what they all mean and where they came from. The one that killed me was, "They also say "ponage" but I don't know what that means."
ETA: In a miracle of timing, XKCD has put up a chart
designed to kill my good mood.