Tyburn, I know it is easier said than done; however, everyone should set up a "rainy day" fund bank account. Ideally, this fund should contain enough money to pay all your expenses for 6-9 months. The amount is different for each person depending on one's budget. Every expense (housing, food, heating, etc.) should be recorded and a monthly average should be determined. If you lose your job or are unable to work, your "rainy day" fund can help tide you over until you are back on your feet. It can also be used to cover unexpected expenses: such as the error in the gas bill (or a dental emergency, vet bill, house damage, etc., etc., etc.). Like I said, I know it is difficult to do, but I thought I would mention it as a financial goal for your future.
"Be of good comfort, Master Ridley, and play the man! We shall this day light such a candle, by God's grace, in England, as I trust shall never be put out."
--Hugh Latimer, October 16, 1555