At the end of Robert Heinlein’s short story “All You Zombies”, the protagonist, who has managed through gender re-assignment and time travel to be his own mother and father, seems trapped in his own narcissistic circle of causality. After he has completed his cycle of movement and ‘movements’, he speaks to an unnamed other of his loneliness, only to ask of the rest of the world “I know where I came from—but where did all you zombies come from?”
His zombies, it seems, are the agentless walking-living, that teeming mass of people who aren’t causes of their own existence, who look outward for will, meaning, and mission. Zombies, thus, are easy metaphors for the automatic behavior of human beings—the way we mindlessly consume ourselves and the world around us from the moment we’re born until we die. Not being a zombie is, on one hand, a losing battle against appetite and attrition. Not thinking about zombies? Something different altogether.