To have refinement in taste and manners. To be refined, well-educated or wordly. May apply to manners, dress, language or lifestyle. Learned in the way of civilized society.
Someone who knows everything featured on the internet, in movies, in the music scene, or on TV, and uses it in daily life (and makes it cool not geeky). If you say something remotely close to a line from a movie, they might quote it. Want to know anything about a youtube video you haven't seen yet? Ask the pop cultured guy.
They probably use lol in real life.
"Dude, Steve just referenced Star Wars, Kanye West, and Rick Roll'd in the same 5 minutes."
"Yeah, he's so pop cultured."