I've been reading his book The Tennis Partner , which has taught me the way Sherlock Holmes observes others. Verghese can't even stop himself observing naked tennis players in the locker room. On one man he saw a profusion of serborrheic keratosis. The next minute he came up with the idea of "Leser-Trélat sign" - a rare condition in which a slew of the usual seborrheic keratoses signifies an underlying malignancy.

Years ago, when I was a medical student, I picked up the habit of religiously observing passengers on a train or a bus. That's how our eyes, from habit, study people and look for diseases. A swollen neck with protruding eyes. A feeble liver from too much alcohol. And indeed, from time to time during my intern year, I found myself gauging the size of veins on others as if I have to insert peripheral intravenous catheters for them.

Try as I might, though, my habit can never be as professional as Abraham Verghese. One of my favorite quotes remains that of Verghese: "If you get on a hospital elevator, don't get off without making at least one diagnosis on your fellow travelers."