The Milly-Molly-Mandy Stories (1928) by Joyce Lankester Brisley opens with the following verse:

It’s good to be sitting still,
And it’s good to be running wild,
And it’s good to be by yourself alone
Or with another child.

And whether the child’s grown up,
Or whether the child is small,
So long as it really is a Child
It doesn’t matter at all.

A trampoline lets you be a child again whether you are big, or small.

Author: Bob Bounce