When I was an intern the Durham VA Hospital, there was a sign taped to the ceiling of one of the workrooms. It said in big, bold letters: SUBDURAL HEMATOMA/PULMONARY EMBOLUS. This was to remind all house officers, at work in the middle of the night, about likely diagnoses for mysterious or confusing diagnostic puzzles. When you slapped your head in desperation and looked up, you would see the answer. So, who knew I went to medical school to save my own life?