I was looking at a human body, a woman sliced in cross-sections no more than an inch thick and pressed between glass so that curious people like me could see their insides up close and personal, learn how it all stacks up. This, of course, is expensive but standard science, like drilling into glaciers or carbon dating. You can tell the age of a tree by counting its rings, but first you have to cut the tree down. These sorts of experiments are irreparable, we call it knowledge. If cut or broken, even if just bruised, the human body can only heal during sleep. This is because rebuilding takes so much energy and such incredible concentration-much like forgetting. My friends who have had children cannot remember the pain of giving birth. When they talk about it, their eyes go wide as if to say Isn't it a miracle?