Parents often feel a kind of existential anxiety as they watch their children grow up—as we say, it goes by so fast. We watch that infinitely flexible, contingent, malleable future swiftly harden into the irretrievable, unchangeable past. Japanese poets have a phrase, mono no aware, for the bittersweetness inherent in ephemeral beauty—a falling blossom or a leaf in the wind. Children are a great source of mono no aware.
