Answer:
Underestimating personal expenses
Step-by-step explanation:
Be sure to include all annual, quarterly, and monthly expenses, including your rent or mortgage; car payments, car insurance and gasoline bills; credit cards with outstanding balances; gym membership; grocery bills; and everything else you’ll spend money on in the coming year. Underestimating personal expenses is one of the biggest mistakes a new business owner can make. If you slip into the red, chances are your business will, too. Its in the book :)