You're not wrong, but how many people consider their opportunity cost in most money-related matters? That is, every year around tax time (in the USA), I see se

You're not wrong, but how many people consider their opportunity cost in most money-related matters? That is, every year around tax time (in the USA), I see several people trumpeting about how folks who get tax refunds did it wrong. "You should have taken a larger paycheck and put the surplus in an interest-bearing account!", they always exclaim. And they're right. People should have done that. But most people wouldn't have. A tax refund ends up being like an unseen piggy bank for a lot of people. They're not earning interest on that money, but at least they're saving it and not spending frivolously. Without that unseen piggy bank though, a lot of people wouldn't have the discipline to save that money.