...here we have the first lesson about the nature of memory: what you wish to forget, you may not be able to. What seems to have died, perhaps is just asleep. On the other hand, sometimes you wish to remember something, and there it stands at the doorway of your consciousness, and refuses to come in. You know you know something, the name of some useless celebrity, perhaps, and yet you cannot fish that name out of your inner aquarium. And this illustrates a critical feature of memory, which resembles, as it turns out, most of the processes in the internal realm: the same cause will regularly yield different, even opposite effects.