The story goes that when chess was presented to a great king, he was so impressed by the game that he offered its inventor any reward he desired.
The inventor appeared humble, which in hindsight should have worried the king.
He asked for something seemingly tiny: one grain of wheat on the first square of the chessboard, two on the second, four on the third — doubling on every square after that.
The king laughed. It sounded cheap. So he agreed immediately.
But after a few rows, the royal accountants started panicking.
The inventor had not been thinking linearly. He had been thinking exponentially.
At first, the numbers looked harmless. Then uncomfortable. Then illegal-looking.
By the final square, the king owed:
264 − 1
More than 18 quintillion grains of wheat. Far more than the kingdom could ever produce.
By that point, the king had essentially agreed to the worst subscription plan in history.
Compound interest is a powerful tool for building wealth.
Debt also compounds.
And just as wealth can multiply exponentially, unpaid debt can grow into a devastating financial burden.