you're standing around with your friends, and something silly comes on the radio. so you start to silly dance. your friends encourage you with giggles. the understanding is that you're all laughing together, tickled by the same ironic, unmerited enthusiasm, but wait--are they also laughing at you? how different is your silly dancing from your actual dancing? i would venture to guess that the moves are perilously similar. before you know it, you're sort of actually dancing, and you won't remember when you crossed the line.
i can think of only one, maybe two people in my life who dance in earnest no matter what the circumstance, and the pivotal differences between me and them seem to be facial expression and movement of the arms. i've given this a lot of thought. dancing is difficult for shy people, you know.