Tire Issues

Last week, the world's cutest little old lady was driving behind me. She got my attention at a traffic light and managed to convey that my back tire was flat. (D shaped, it was so flat.) I thanked her and put air in it. Today, the same tire was flat again. I took it in to a tire center prepared to pay for two new tires and maybe a other new parts, depending on how much damage I'd done driving on it. Fifteen minutes later, the charming young man who had my car came back and informed me that my problem was simply that I had picked up a screw. He removed it and patched the leak free of charge AND I wasn't even late to practice!