“When children are playing alone on the green,
In comes the playmate that never was seen.
When children are happy and lonely and good,
The Friend of the Children comes out of the wood.
Nobody heard him and nobody saw,
His is a picture you never could draw,
But he’s sure to be present, abroad or at home,
When children are happy and playing alone.”
(R.L. Stevenson in The unseen playmate)