Traumatic brain injury leaves an often-invisible, life-altering wound

The doctor begins with an apology because the questions are rudimentary, almost insultingly so. But Robert Warren, fresh off the battlefield in Afghanistan and a surgeon’s table, doesn’t seem to mind. Yes, he knows how old he is: 20. He knows his Army rank: specialist. He knows that it’s Thursday, that it’s June, that the year is 1020. Quickly, he corrects the small stumble: “It’s 2010.”