In the olden days (pre-MTV, at least), slang was pretty easy to keep up with because you were pretty much limited to the group of people you hung out with. With rap and hip-hop all the rage (still), it seems there’s tons of new slang erupting every day. As soon as you think you have mastered it, it’s outdated and something else has taken its place.
It doesn’t help when one performer (Snoop, I’m looking at you) has his own slang.
Perhaps I’m not supposed to know. Maybe that’s how them young’uns keep secrets from us “old” folks (40+).