One day, while discussing the mystery of our patient at the hospital corridor, my colleague who has a passion for automobile mechanic cautioned, "Oh man. If we want to be honest, let me ask you how many times are we doctors certain with what's wrong with our patients?"

Slushy nonsense? Not a bit of it! For some reason I'm amazed at his cruel and frustrating (though certainly true) statement. Consider an eightysomething man who came to the hospital with a bit of cough and not in his usual shape. Each numerical figure in his laboratory results was not very normal, but not too bad. At the end, for the hundredth time, for the thousandth time, the diagnosis, often loopy, would be a chest infection. It's hard to imagine any better diagnosis to be typed in the discharge summary.

Which brings me to the analogy of an auto mechanic, this time attributed to David H. Newman. Consider going to an auto mechanic about an unsettling sound coming from the car. The mechanic also suspected something (but not sure which) wrong. He then shrugged and produced a pair of earplugs - alas, quite similar to what we prescribe - and said, "Wear these while you drive."