Confession Time: I was one of those teens who was afraid to dance.
I thought that everyone was watching me. And I didn't know what to do, because weren't there moves or steps or something? Also I don't like this song, let's wait for a good song.
But I did learn to dance. Mostly, I stopped caring so goddamn much. It helps if you're willing to get a little tipsy, and if you have a friend who will (loudly) verbally encourage you. But the main point is that dancing is a form of play- and most adults suck at play. We take it too seriously, and try to think too much in words, rather than kinesthetically.
And that's why couples who dance are always precious and beautiful, even if they're just shuffling around the floor. Because when you are playing with your favorite person in the world, joy just rolls off of you.