Reading Paul Kalanithi's memoir got me thinking - ha ha, brain surgery, thinking, i kill me - a lot again, as you do every now and then and then have to stop because it makes your head hurt, about the whole question of what makes a person, and the whole intractable problem of metaphysics - trying to come at the issues of being in the world from outside the world, where you can never be - and the mind and the soul and how trying to use the brain to think about the brain is very, very difficult, especially when your brain is forty-something and has raised two kids and weathered a lot of tequila shots. Have you seen those medical shows where someone comes into the hospital with something sharp stuck in their brain, and when it gets removed they're ostensibly fine, but their personality has changed, like they're nice when they used to be cranky, or cranky when they used to be nice? Is that not really, really freaky? Something could happen to one tiny part of your brain and ...