I don’t know what world you live in, but in mine, people only do things for you for one of two reasons. The first is if they want something in return. And the second is if they feel like they owe you something.
Dancing is so wonderful. Once they start the music, your whole day, if it's been rotten, seems to melt away. You get carried away in the tune that you're moving to. It's a marvelous catharsis, to be able to get on top and tap dance.