Thinking, for Sam, was necessary, and the pain made him feel stupid, an entirely new phenomenon for him. Sam’s doctor said to him, “The good news is that the pain is in your head.” But I am in my head, Sam thought. Sam knew the foot was gone. He could see it was gone. He knew what he was experiencing was a basic error in programming, and he wished he could open up his brain and delete the bad code. Unfortunately, the human brain is every bit as closed a system as a Mac.