During my surgical residency I was called out of a sound sleep to the emergency room. Unshaven and with tousled hair, I showed up with an equally unpresentable medical student. In the ER we encountered the on-call medical resident and his student, both neatly attired in clean white lab coats.
The resident said to his student, "You can always tell the surgeons by their absolute disregard for appearance."
Two evenings later, I was at a banquet when called to the ER to suture a minor laceration.
I was stitching away -- wearing a tuxedo -- when I encountered that same medical resident. He looked at me, then said to his student, "Sure is sensitive to criticism, isn't he?"