Answer: Record keeping
Explanation:
A person's net worth is calculated as the total assets they own minus the total liabilities they owe. As such it will be very important to keep records so that you know what you own as well its value as well as what you owe as well.
Taxes are no different. The better the records you keep are, the more accurate your tax payments will be. Without proper records you could overpay taxes which would mean you lose money or you could underpay taxes which is a crime.