The last of a three-part series on why families should not have more than one child.

And the most important reason not to have more than one child: Raising a child is hard—and it gets harder as the kid gets older.

My dad wrote a book about raising kids, called A Child to Change Your Life. In the introduction, he wrote, "It is terribly easy to create and to love a little child. But it is a terribly difficult and consuming job to mold one into a good human being. I think those of us who have been through the whole experience owe it to those who haven't to tell them what it's really like. And maybe to acknowledge that both the people who decide they can do it and those who decide they can't make equal contributions to the world of happy, helpful human beings."

The degree of difficulty and complication in raising a child increases as the kid gets older. You begin to see the size of the challenge when you ask  her, picking her up at pre-school, "How was your day?" She says, "Good." And when you try to get more than that, she looks at you like a soldier who's been asked, "How was the war?" It was fucking complicated, Dad.

Infinitely so.

So you ask a few questions—what was the best thing that happened? what was the worst?—and then you talk about what's for dinner and what time Mom's coming home and how many days until Santa comes. And then, three hours later while the two of you are molding meatballs, your kid says, "J.R. has a crush on me and I have a crush on him and Amelia told everybody."

Or he says, "Uncle Larry paid me five bucks to rub his feet."

Or she says, "You know what, Dad? I don't like dreams. Because they're bad if they're scary, and if they're good, you're mad when you wake up."

That happens every single day. And after awhile, you get to know your kid—or at least begin to, if you concentrate and listen and question and keep yourself from stifling the kid's candor, which you will often want to do.

Now how are you going to make yourself available like that if you have two or three kids? The squeaky wheel gets the grease. But every wheel needs the grease.

Look, in the end, I'm not saying that you shouldn't have more than one kid. I have seen many happy and healthy families with multiple kids. "I'm happy with my three boys, actually," says Chicago speechwriter Dan Conley. "I was born for this role." I never argue with a happy man, I told him.

And meanwhile, my three-part family ain't no picture of perfection. Ask Scout in 10 years; I'm sure she'll give you chapter and verse.

I'm just saying that, to my great surprise, I increasingly find myself wondering, not whether Cristie and I have made a mistake with our personal one-child policy, but whether conventional wisdom has driven other parents to overcrowd my dad's optimistic "world of happy, helpful human beings."

Part two in a three-part series on why families should not have more than one child.

And here's the second reason I'm glad I had an only child: I want her to know the real me.

I've often quoted my late pal Ed Reardon—father of four—who told me there is no such thing as parenting. Your kids just watch you for 18 years, he said. If you're good, that's good. If you're bad, that's bad.

Well if that's true, and I believe it is, then I want the person my kids to see to be me, and not a logistics-obsessed, vacation-sacrificing, money-panicked, bank-robbing, overwhelmed, friendless, humorless, exhausted Parent Person.

Because we have been so selfish as to have only Scout, she sees us at play. I often take her golfing with me and while I putt, she collects acorns and chases catch dragon flies. That works with one kid, not with two—as does an afternoon of kicking around town with Mom. Because we have been so selfish, she sees me write, watches us read. She sees us sleep and work out and cook big meals and drink beer on the porch with neighbors and visitors from out of town. She watches me ride off on adventures on my motorcycle and she watches her mother utterly relax with her family in Des Moines. Because I have been so selfish, she has been to many places that we could not have afforded to take two or more kids, and she'll see many more—and she'll see us enjoying those places and living life in much the same way as we lived it before she came along, and will live it when she is out of the house.

Obviously, I'm drawing a caracture of parents of two kids, but the caricature is based on an observation that, if you have two kids you might as well have five. And if you have more than two kids, as a friend put it, "Now you're playing zone."

And I'm also I'm glorifying the wonders of these wonderful lives Cristie and I lead. Hemingway and Gelhorn we're not. But Cristie and Dave, we still definitely are.

Meet me back here tomorrow, when I argue that, in families of multiple kids, the squeaky wheel gets the grease—but every wheel needs the grease!