Purple Heart by Patricia McCormick
While stationed in Iraq, Private Matt Duffy is injured while out on patrol. He remembers he and his squad chasing a vehicle, then continuing on foot into an alley. He remembers gunfire, and a rocket-propelled grenade hitting the wall behind him.
After that Matt remembers nothing. TBI the doctors call it, traumatic brain injury where his mind shuts out any other details of the event, as well as his ability to recall simple everyday words and actions. As he works to regain cognitive functions, Matt begins to get flashes of what else may have happened in that alley that day. He slowly realizes that he may have killed a civilian, a child. Or did he? His memory is still fuzzy and unreliable, leaving Matt struggling to learn the truth.
McCormick creates an interesting story, really generating a feel for what day to day life may be like for an injured soldier in Iraq, emphasizing that what the rules are and what is really acceptable can be two very different things.