It’s not a point of pride for me to say I had little idea who Korean pop supergroup BTS was before this week. As Fortnite weaves its tendrils into the world of pop culture, I find myself frequently asking younger colleagues about musicians, movies, and fandoms in a way that looks less like disaffected cool and more like I’m just old and out of touch. Tonight, BTS premiered the choreography video of its recent hit “Dynamite” in Fortnite, and I dutifully buckled in to feel Too Old once again.