My Uncle Ralph is one of my heroes. He's over 80 years old, has had more than 19 surgeries in his life and he can still do a one-handed pull up. Not that he exercises much.

"Exercise is just stupid!" he says. "Why would I burn all my energy exercising when I can just go to work and do something useful?"

The pull-up occurred when he was nailing in rafters for a shed he was helping to build.

"Get me that ladder," he said, but when I was too slow, he just swung to the next rafter, Tarzan style, pulled himself up with one arm and nail-gunned with the other. Then he looked at me with my mouth open and said, hanging there, "You gonna get me that ladder now?"

Uncle Ralph is a philosopher genius. On the subject of mistakes, he claims a certain expertise, which I learned when he helped me rebuild my old house. (He's also a master builder and cabinet maker). When I cut a 2-by-4 on the wrong side of the line, he said, "Good, now do it right." When I made the exact same mistake the second time, he said, "Good, now do it right."

When I asked him "Why 'good'?" Uncle Ralph stopped hammering and waxed philosophical.

"I'm not saying that it's good to make mistakes, but when you make them, you learn how to do it right," he said. "If I don't make that mistake now, it's only because I've made it a hundred times when I was younger."

Which is all well and good if it's a 2-by-4, which I can re-use, or even burn in the fireplace on a cold winter day.

"Not so good if it's a patient," I said.

"Well, that's why you call it the 'practice' of medicine," he said, hammering again.

In my intern days, I remember learning by the "see one, do one, teach one" method about how to draw blood, put in IVs and foley catheters and take blood pressure. I remember pumping up a blood pressure cuff that I had put on inside out, while my patient spoke Urdu to her daughter, probably commenting on what an idiot I was. I think about her every day, and I have never made the same mistake.

There are other mistakes I know I will never make again. I will never, for example, ask the following question: "Oh, how many months pregnant are you?" unless I have personally seen the pregnancy test.

I will never, ever, again refer to my patient's young male companion as her son, only to be told "I'm her husband!"

There are, of course, those challenging times, like when a husky voice answers the phone and you say: "Mr. Jones?" only to be told "No, it's Mrs. Jones, honey. I'll get Mr. Jones." So, in cases of uncertainty, I've learned to just pronounce the consonant "z." Thus, "Hello, zzz Jones," which can pass for Ms., Mrs., or Mr.

Of course, such problems would never bother Uncle Ralph, who once asked a young niece, "Are you pregnant, or just getting fat? Either way, you look good because you used to be too skinny."