For "life and death" doctors, which I'd include eye people, it's in part a defense mechanism. They know some day, if not already, they're going to make a mistake that will kill a patient, and they've got to be able to accept that and carry on.
One of the reasons I dropped that as a possible career, and one reason I like software and systems, for with a modicum of care you can recover from most mistakes.
You've never hung around with doctors outside of the hospital, clearly. Their egos, in general, dwarf any I've encountered in software or hardware.