A what in my head?

Illustration fodder: A man in Littleton, Colorado, went to the dentist for a toothache and discovered he had accidentally embedded a nail in his skull six days earlier. He's doing well following surgery. The strangest part of this story, though, is a quote from a neurosurgeon at the suburban Denver hospital: "This is the second one we've seen in this hospital where the person was injured by the nail gun and didn't actually realize the nail had been imbedded in their skull."