Followup to: Rationalist Storybooks: A Challenge

This was originally a comment in response to a challenge to create a nursery rhyme conveying rationality concepts, but, at the suggestion of Eliezer, I've made it into its own post.

Little Johny thought he was very bright,
But the schoolkids did not -- they would laugh when he came in sight.
He could count, sing, and guess the weather.
Then one day, Big Bill said "Real bright boys will grow a feather."

"Ach!" he cried, "Could it be true?"
"Then I'm not bright, which makes me blue."
So he went home, and searched all over.
And then found growth on his head, clear as a clover.