The average individual (child or adult) would not voluntarily take up square dancing.
But, in a group of 25 people square dancing, that same individual would participate.
Because everyone else is doing it. Therefore, it doesn't seem quite as silly.
And, when everyone else is doing it, who wants to be the odd man out?
It's all about the crowd.
Find the thing you want to do, and find a crowd that's doing that thing.
There's power in community. And it's there for everyone.