When I went to get into my car after the oil change, I stuck the key in the ignition and gave it a turn.  The lights dimmed and it just made a chattering sound.  Great, a dead battery.

And, I knew why it happened.  The head lights will stay on as long as the drivers door is open.   And, since the mechanic was trying to reset the maintenance indicator, he was sitting in the car with the drivers side door open.  Thus the head lights stayed on for a half hour, thus the battery went dead.

I quickly went back into the office and announced my dilemma.  Moments later, the mechanic appeared with a battery boosting box and got me started.  Great!! I was tired and hungry and just wanted to do home.