In this world in which we live simplicity and kindness are the only magic wands that work wonders - L. Frank Baum

All the same,' said the Scarecrow,'I shall ask for brains instead of a heart; for a fool would not know what to do with a heart if he had one.'
'I shall take the heart,' returned the Tin Woodman,'for brains do not make one happy, and happiness is the best thing in the world.

Of course you don't know. Nobody knows why; we only know it's so, and can't tell why it's so.

"But I cannot flash fire from my eyes unless I am very angry."
"Can't you get angry 'bout something, please?" asked Ojo.
"I'll try. You just say 'Krizzle-Kroo' to me."
"Will that make you angry?" inquired the boy.
"Terribly angry."
"What does it mean?" asked Scraps.
"I don't know; that's what makes me so angry," replied the Woozy.