On September 13, 1848, this man was filling in a hole with gunpowder when an explosion caused him to allegedly become "no longer" himself.  
This man was once exhibited by Henry Bigelow to the Harvard Medical School alongside a stalagmite "remarkable for its singular resemblance to a petrified penis".  A photograph of this man rediscovered in 2008 was long thought to be of a man attacked by a whale.  The cover story of a 1994 issue of Science was about a recreation of this man's accident by Antonio and Hanna Damasio.  Late in his life, he drove stagecoaches in Chile and apocryphally went from town-to-town re-selling rights to his (*) corpse to medical schools.  His remains are the highlight of the Warren Anatomical Museum.  "Obscure country physician" John Harlow had to stick two fingers in this man's head to operate on him.  On September 13, 1848, this man was filling in a hole with gunpowder when an explosion caused him to allegedly become "no longer" himself.  For 10 points, name this man found in countless neuroscience textbooks under the heading, "the American Crowbar Case".
This man was once exhibited by Henry Bigelow to the Harvard Medical School alongside a stalagmite "remarkable for its singular resemblance to a petrified penis".  
Phineas P. Gage