Anatomy of a bad mood: You must prepare to have one. So start out by taking an Ambien the night before, to help you sleep. After all, if you haven't gotten much sleep lately and things have been OK, lots of sleep will make things awful.

Wake up after said sleep feeling groggy. Sleep was full of dreams despite (or perhaps because of) drugs. Out of bed late, your son playing happily in his room. Shower. You can't remember what you've washed already... soap is lathery, so it's a fair bet you've used it. But what about the face soap and the shampoo, both of which come in bottles? Just in case, you use them again.

Breakfast proceeds without incident. Off to Gymboree, where an overly perky teacher leads you, one other Dad, and a thousand Moms in sickeningly precious songs and games. Your son enjoys it. Ritual is, after Gymboree, go have lunch with Mom at her office. Mom has a meeting. You go home. Son screams. You apologize and offer to make his favorite lunch, mac 'n' cheese. Son stops screaming.

Reasonably awake until you realize there's nothing for you to eat for lunch. Wave of exhaustion. Trip to grocery store, where son, mischevious but in a good mood, tries to pull all sorts of things off the shelves. Pay bill. Go home.

Put groceries away. At least the refrigerated items. Too tired to put the rest away. Plastic bags in a heap on kitchen floor. Dog and cat hair everywhere. You sneeze. You were never allergic to anything until you moved to D.C. Son running this way and that, not really misbehaving, but very annoying. He looks tired too. Nap time.

No! He does not want a nap. Hits you. You lose your temper, shout, not just any old shout, but the old ripping-the-vocal-cords-to-shreds shout. He stops. You realize this shout is the only foolproof way to get him to behave. Depresses you even more. Put him in bed and sit in front of the computer for no real reason. He leaves his room. You put him back in bed, notice he's pulled all the bedsheets out of the bottom drawer of his dresser. You put them away, start to stand, bang your head on his diaper changing table. The shout is heard as far away as New England.

You lie down in bed, near tears, manage to catch a little sleep. Your son does not. You give up. Sleep, which usually helps, has managed to make you even more wretched. You both go downstairs, where you sit on the couch, a nervous wreck, as your son runs around, not a care in the world.

Wife comes home. She sympathizes. You repay her with snappishness. A minor disagreement after dinner (which somehow you managed to cook) becomes an argument. You trudge upstairs and lie down again, not coming down until your son's bed time. By this time, son has worn down his mother, too. A winning combination. You think about abandonment, suicide, other happy concepts.

Up to bed for the son. Still running, still laughing, now and again crying because he's finally tired, too. Read a story. Lie him down. Look at him. Hug, which he returns. And the whole day melts away. You cannot leave these people. You love them too much. You need them and somehow they need you, too.

Sit back with the wife and watch an episode of Buffy the Vampire Slayer. Stay up late playing hand-held Yahtzee. Go to bed at last, without the Ambien this time. And wake up the next morning, the world a better place.