Economists call it opportunity cost. In practice, it’s one question: what else could this money be doing? Consider a $200 impulse purchase. On its own, it’s harmless. But $200 a month, invested at a 7% average annual return, is roughly $34,000 in ten years. The purchase isn’t competing with your bank balance — it’s competing with the version of your future that money could have funded. This isn’t an argument for never spending. It’s an argument for spending knowingly.