If you can stomach the shaky camera work in the following video, then you will be justly rewarded. The place is some outdoor concert in a park or field somewhere. The focus of attention is a guy who dances crazily on the grass by himself. It's kind of embarrassing, really, but then another guy joins in and then another. Soon, the individual joie de vivre of a dude with no shame becomes contagious. Alas, this is the evolution of a dance party. Watch:
If I were there, I of course would've been the sole holdout, sitting stubbornly with my arms crossed. "Harumpf!"
[Courtesy of Will Blank.]