In a certain kingdom in olden days it was the custom to choose a king by the will of heaven.  A rare bird, known as the Bird of Happiness, was sent forth when the king died, and whomever's head the bird rested on, he became king.  Once it came to pass that when the ruling king died and the bird was sent forth, it rested on a slave's head.  The slave used to earn his daily bread playing the drum and dancing at weddings, dressed up in feathered cap and wearing a belt made of lamb's hooves.

When the slave was chosen as king, he ordered a small hut built near the royal palace.  He put inside it his treasured possessions, his feathered cap, his belt made of lamb's hooves, and his drum, as well as a big mirror.
The ministers wondered very much and asked the king to explain his strange behavior.
- You have to gard your dignity even when you are alone, - they reprimanded him.
The king answered: - I was a slave before I became king.  Thus I want to remind myself that I was a slave.  Only then will I not imagine myself greater than you and other men; only then will I not feel proud in my heart.