Once upon a time there was a little boy and his little sister. And they lived in a town with NO swing set. And you can't tell, but this made them sad. Real, real sad.
And they dreamed and dreamed of a playground that would have a swing set and a slide and maybe some kind of yellow animal springy thing.
And then one day it fell magically out of the sky and the little boy and the little girl were SUPER happy.
(only that's not exactly true. A ton of people did a ton of work to make it happen.)
And all the kids in town came to play at the brand new playground. And they were so happy they never wanted to leave even though there must have been some weird thing in the water that made them all look exactly the same even though they weren't even related. Except, you know, the little boy and his little sister. They were, in fact, related.