" Like all young people, he has no idea who his parents really are; for eighteen years he has experienced their existence only insofar as it has related to his own needs. Suddenly his mind is full of questions. What do they talk about when he’s not around? What secrets do they hold from each other, what aspirations have been left to languish? What private grievances, held in check by the shared project of child rearing, will now, in his absence, lurch into the light? They love him, but do they love each other? Not as parents or even husband and wife but simply as people—as surely they must have loved each other at one time? He hasn’t the foggiest; he can no more grasp these matters than he can imagine the world before he was alive. "

― Justin Cronin , The City of Mirrors (The Passage, #3)