But a doctor learns, because he has to, not to worry actively about patients until the worrying can do some good; meanwhile, they have to be walled off in a quiet compartment of the mind. They don't teach that at medical school, but it's as important as your stethoscope. You've even got to be able to lose a patient, and go on back to your office and treat a cinder in the eye with absolute attention. And if you can't do it, you give up medicine. Or specialize.