Babies tell us nothing about infancy because they can't speak. And our beginning, of course, like all beginnings, tells us nothing inevitable or predictable about our middle or our end. Monogamy as our beginning and our end is too wishfully neat, too symmetrical for the proper mess that a life is.
But if monogamy is where we start from, our first knowledge is of infidelity: that is what knowledge is about. Temporarily the mother can be everything to the child, but the child cannot possibly be everything for the mother. He can't feed her or sexually satisfy her, or have adult conversations with her. From the child's point of view the mother is—as the father will soon be—a model of promiscuity. She has a thousand things to do. She knows other people.
Small children, like uxorious husbands, are the most devoted of partners to their parents (they like coming with them to the toilet). Their parents, however, libertine if only in their responsibilities, have other commitments. Small children understand monogamy. Adults often find it daunting, even beyond them.
