A receipt proves you paid. It doesn’t prove it was worth it.

Proof of payment and proof of value are different documents, and only one of them exists. You can show exactly what something cost and there is nothing to show whether it made your life better, which is why people defend purchases long after they have stopped enjoying them. Money spent feels like a commitment. Admitting it was not worth it feels like losing twice.

A week after you buy something, ask whether you would buy it again at the same price. No consequences attached to the answer. Doing that a few times will teach you more about your own spending than any budget.