Futurama scene where Fry has been transported to the year 3000 and he still has his ATM card: The bank teller checks Fry's bank balance. She says, "You had 93 cents in your account in 2000. With an average interest rate of 2.25% compounded for 1000 years . . . that brings your balance to $4.3 billion dollars."

The math is correct. Plug those numbers into the compound interest formula, Pn = P0 (1 + r/100)^n, and you really do get $4.3 billion.

Your gut feeling is that even with 93 cents, you could retire rich. Not a billionaire, but comfy. It ain't so. In 50 years, you'd have $2.83. And even that $2 gain would be wiped out by a single monthly banking fee :-).

In 400 years, $6820. My intuition told me that I should be in the millions by then. Wasn't even close. Didn't even account for taxes and inflation.