Then one day, over the winter, the red swing got broke. They replaced it with a green swing. You liked the green swing, but never as much as the red swing. You also started noticing the big girl swings. Soon, you wanted to ride the big girl swings. I lifted you up and pushed you, because you didn't know how to pump your feet yet. You loved swinging in the big girl swing more and more, and you got better and better at it. Soon, you demanded that I swing as well, then we would both swing together on the swings, although I had to stop every so often to give you a push.
And that's how you came to swing in the big girl swings.