Don’t owe favors to people who keep score. Their interest rates are brutal.

Some people give in order to hold something over you later, and the help arrives already priced. You can usually tell because the favor gets mentioned, counted, brought up in unrelated arguments. What looked like generosity turns out to have been a loan with terms you never saw.

Before accepting help from someone like that, ask what it will cost when they decide to collect. Often it is cheaper to pay for the thing, do it badly yourself, or go without. Keep your debts with people who would be embarrassed to mention them.