I used to come home every night to a childless house, and I was happy. But since my daughter's birth, if I come home and she is away for the night at a grandparent's house, my evening goes poorly. I check the video monitor of the nursery and feel empty to see an empty crib. My evening walk, without her in a carrier against my chest, is exercise without pleasure. How can I be dependent on a being who, six months ago, did not exist? I did not need her when I did not have her. But she has entered my life as a nail enters a block of wood, simultaneously creating a hole and filling it. Remove the nail, and the hole remains. Love completes unhappy people, but uncompletes happy people, because love means we can no longer be happy alone.