From a good article the other day about retired Army Col. Eric Welsh by Mark Davis of the Atlanta Journal-Constitution:
Welsh recalls July 2, 2007. His Humvee was rolling along a road in Mosul when he heard a boom, felt the vehicle shake as if the ground was about to swallow it. The force of the blast knocked him out. When he came to, Welsh, shrugging off his latest concussion, returned to his troops. A physician stopped him. How many blasts does this make? the doctor asked. Welsh thought. "I don't know," he replied.