For the last several weeks I have been trying to wrap my mind around this story about the iconic brain surgeon, Allan Hamilton, M.D. Why? Because he’s finally launching his big book, Cerebral Entanglements: How the Brain Shapes Our Public and Private Lives. He’s been working on this one for years, and I know that because stories in the book have appeared in this magazine. What happens is that we talk on the phone, our brains get entangled, and then a feature begins to grow at AZTECA, his famed surgical simulation lab at the University of Arizona. Allan thinks in pictures (he first wanted to become an artist), and he can produce words about…