Long ago, the Shah of Persia ran out of enemies to fight.
He loved battle, and was so bored that he issued a challenge to his empire: Whomever invents a battle-game that entertains him will be granted whatever prize he wishes.
A few months later inventors from around the empire arrived at the great palace and showed off their inventions.
The shah went from stand to stand, with nothing capturing his attention.
Until he came across an old man sitting in front of a square board, on which stood 32 pieces of wood of different shapes and sizes.
The shah asked what is this, and the old man said it’s the greatest board game ever. No luck involved. Only the smartest, wisest strategist can win.
The goal was to capture the opposition’s Shah, at which point the winner calls “Shah-maat” (Shah captured) and the game is won.
The shah sat down to play and didn’t stand up for hours as he became absorbed in the game.
Eventually the shah declared the old man the winner and asked him what he wanted.
The old man humbly stood and asked only for rice.
“How much rice?” asked the shah. The old man asked for 1 rice grain on the first square on the board, and 2 rice grains on the second square, and to keep doubling for each square until all 64 squares covered (8 rows by 8 columns).
The shah laughed and said yes, of course, what a cheap prize.
The grand vizier started counting out the grains and halfway through the board realised the total would be more rice than the empire could produce in ten years (18,446,744,073,709,551,615 grains).
The shah realised he had been disrespected and chopped off the old man’s head as a lesson to all his subjects not to disrespect him.
The moral of the story is that the human brain cannot comprehend exponential numbers, ie: compounding interest.
And that you should not be cheeky with people that are more powerful than you.
You’ll lose your head.
PS: The game became known as Chess (a mispronunciation of Shah), and winning became Check-mate (Shah-maat).