When I am very depressed — which is not now — my brain feels solid and hard. It’s the surest guide that I have had the Big One, the low that can only be borne by plodding steps and lowered head. Yea, they will write it off as merely bad posture. I will marvel at the adamantine of my cerebellum, the heaviness of my medulla oblongata. I will ponder the sharpness of the rock inside my skull and, when the feeling has toppled away like a raven falling from a cliff towards its nest, I will desire its return because it is only then that I can feel that I have a brain and am, in fact, alive.