Albert Einstein, arguably one of the most intelligent persons to ever live, said “Compound interest is the eighth wonder of the world. He who understands it, earns it … he who doesn't … pays it.”
I remember being asked which I would prefer as a gift: $10,000, or 1 penny, doubling each day for 30 days.
At the end of 30 days, $10,000 is still $10,000, while what began as $0.01 has become $10,737,418.24. That's right - almost 11 million dollars!
And that's why compound interest is the eighth wonder of the world!
On the other hand, if you have a credit card with a $10,000 balance, at 24% interest, if it was possible to not pay the minimum each month, after 10 years you would owe (drum roll) $84,944.26! If you had paid the minimum monthly payment, after 10 years you would have paid $26,400 in interest, and you would still owe $10,000!