> if a bank loans out the money that you deposited, both the borrower and you can spend it.

When you "spend" money that you deposited with the bank, what you're actually doing is getting the money you lent to the bank paid off.

What's the difference between that and you lending money to someone to buy a bagel/T-bond, and then at some point in the future, getting money back so that you can buy a sandwich/car?