Sixteen years ago, a man stood alone on a grassy hill during a music festival in Washington state, USA, and began dancing by himself. People looked, then looked away. Some laughed. His roommate walked over and told him he was being filmed.

He didn’t stop.

Then, a stranger stood up and joined him.

Then another.

Soon, the hillside began to shift. Within minutes, hundreds of people were running across the field to take part in something that, just thirty seconds earlier, had been one man being laughed at in a field.

Someone filming from higher up the hill whispered: “Look what one man can do. One man can change the world.”

The video went viral in 2009. Entrepreneur Derek Sivers later showed it in a TED talk to explain how movements really begin—not with the first person brave enough to start, he argued, but with the first person willing to join. Collin Wynter, the man who danced alone, later said he had no idea he had done anything special. He was simply tired of seeing everyone sitting around doing nothing.