Six months ago my friend Mary told me that she now has a new pacemaker to replace her ten-year-old one.
    "Wait," she said. "Take a look." She took the piece out of her pocketbook. "This is similar to your pacemaker. Yours is a bit smaller."
    Mary handed it to me. "You can have it."
    "I'll borrow it," I said.

    That afternoon, at my six-month checkup, my primary care physician asked many questions about my health, sitting on a stool as he updated my chart.
    "How is your pacemaker working?" he asked.
    "Oh, I didn't like it," I said. "So I disconnected it and took it out."
    As I spoke, I removed Mary's pacemaker from my pocketbook and held it toward the good-natured doctor.
    There was a split second of silence, before the doctor jumped off the stool and said: "You're messing with my mind!"