@Fatal Freedoms,
Suppose There are 100 dollars in the whole world, John has $5 and Paul has $95.
John Borrows $10 from Paul at a 10% interest rate each month. So john now has $15 and Paul has $85.
But John waits 60 months too long and now owes 600% interest plus the $10. So Paul has $85 and John has -$610.
John does some work for Paul and gets paid $85. So now Paul has $0 and John has -$520. The money supply has gone from $100 to -$520 through the application of interest.