I know why men are so insecure. My uncle wore his hair long well into his forties, plays guitar in a band and still rides a motorcycle. My bachelor friends lap up the glossy machismo packaged in Maxim and The Man Show to prepare for their apparently swinging lifestyles. Every Monday morning, a former co-worker used to regale the office with tales of weekend sexual conquests, in case we doubted his manhood. I used to wonder why these guys clung to the Alpha Male Brand so tightly, but recently I stopped asking. I now know that at some point a mere 20 weeks after conception, before they even took their first breaths, someone had already made fun of their dicks.

My wife Debbie and I stood in a dark room on the 14th floor of Northwestern Hospital, watching an ultrasound monitor with her parents. The technician moved the probe around Debbie's stomach and tapped at a keyboard. This was The Exam, the most crucial to date, as it would spot any potential problems and tell us the gender of our first child. Our eyes misted as we counted ten fingers and ten toes, checked off fully formed organs, and saw the profile of a face. But we hadn't answered the big question. Halfway through the procedure, Debbie asked, "Can you tell the sex is yet?"

"You mean you want to know?" said the nurse. "It's a boy, I knew right away. Here, look." She moved the wand until we saw a shot of the telling genitalia. I drifted off into a scratchy home movie of my son and me playing catch. We built go-carts. I let him beat me at arm wrestling. He threw me perfect-spiral football passes while a soprano-sax score played in the background. Then my mother-in-law cried, "Oh look at his little penis! It's so cute!"

I clapped my hands on the sides of Debbie's belly, hoping Matt Jr. didn't hear. I wiped off the ultrasound jelly, and the nurse pressed a glossy 4x6 into my hands. It was a waist-down shot, with an arrow pointing to his privates, the word "GENDER" printed next to it so we wouldn't mistake it for a stray digit or vestigial tail. It was too late: the advances of modern maternal-fetal medicine had already doomed our son to showering in his boxers after gym class. His still-forming mind was already thinking about the size of his penis, and now he would spend the rest of his life trying to make up for it. The tail of the home movie started flapping against the projector and was replaced by a new image of my middle-aged son picking me up from the nursing home in a convertible Corvette, his comb-over trailing behind the cell phone clamped to his ear.

Debbie and I married at 24, the first among our group of friends. After our honeymoon, we answered the requisite questions about family by joking that we might think about children in 10 years. Privately we agreed that we would know when the time was right. After three years the timing felt right, and soon after we were standing in the ultrasound room. I assumed that an expecting father worried about important things like the baby's health or providing food or teaching right from wrong. That's what Dr. Phil says, and it seemed to be what my parents were most interested in while they raised my older sister and me. But I've never been around babies. My sister doesn't have children yet, and our little cousins live far enough away that I'll only see them two more times before they start smoking and drag-racing their Mustangs. I can take care of my dog, but I doubt I'll be able to leave my son at home during the day with a bowl of water and a piece of rawhide. Given this meager practice, I should be more concerned with how I'll teach my son to read or do arithmetic. But now as I ponder my parental responsibilities, I can't think about these things because more pressing concerns vie for my attention.

I followed the baseball playoffs this year with more anxiety than the previous four seasons combined. I fretted over my team's fortunes like usual, but now I found myself worrying about which team would make my son's stomach turn in October. As a St. Louis Cardinals fan living in enemy territory, I fear for the boy's safety if I send him to school in a red t-shirt amidst all the other little blue-clad Bleacher Bums. I tried to rationalize it as an abstract lesson in individuality, but I suspect his mother would burn his vintage Ozzie Smith jersey the first time he came home with a black eye. So now I'm considering the compromise of encouraging him to be a White Sox fan. Then he could follow a local team but still commiserate with his old man over some good old-fashioned Cub-hating.

I saw the Beastie Boys in concert for the first time this year at the United Center, but instead of enjoying the show I worried about how I could reconcile fatherhood with my musical tastes. I listen to hip-hop, rock and metal, but I always assumed I would grow into more "mature" genres by the time I had children. Now with a baby on the way and me still buying albums with "Parental Advisory" stickers, I'm in a panic. I lie awake at night wondering when it's appropriate to replace Barney and Sesame Street with Public Enemy and Slipknot. I grapple with how I'll translate the lyrics to him ("No, he's not talking about Mommy") or where I'll hide the Outkast CD with the naked woman printed its cover. I know his musical preferences will probably be determined by what his friends listen to, and that by the time he can really appreciate music my tastes will seem hopelessly dorky and quaint. But just like rooting for the same baseball team, I want my son to emulate me without my own choices ruining his enjoyment.

I'm fortunate to not have to worry about Dr. Phil's Childrearing Essentials. I know that I can teach our son mechanical things like table manners or riding a bike when the time comes, and I just assume that he will develop his morality and politics by osmosis, absorbing them as Debbie and I lead by example. But this is what my conscious mind tells me. Subconsciously, I think the burden of producing a kind, responsible citizen of the world terrifies me, so my mind occupies itself with inane details about baseball, music and preempting my son's mid-life crisis.

I grew up in a small, conservative town in southern Indiana where people get married right after high school and finish having children by the time they're 27. But among our peers in Chicago we are scandalously young to be starting a family. Few of them are even dating seriously. Their lifestyles revolve around video games, bar-hopping in Wrigleyville and weekend trips to Las Vegas. Three years ago, mine did too. My friends ask me how I'll manage to carry the baby during the next bar crawl. The notion of familial responsibility is foreign to them, but only slightly more so than to me. None of us are any different from the 19-year-old fraternity pledges we used to be, shooting bottle rockets at each other and drinking straight from the keg. Now we just have jobs and pay taxes. I still giggle at fart jokes; how am I prepared to have kids?

The truth is, I'm not. And I probably won't be ready by the time we have a second child. I doubt anyone is. I should be content solving the silly problems in my mind right now, because I won't be able to comprehend the important ones until I'm swimming in dirty diapers or taking away a set of car keys. No one can plan ahead for parenthood. With any luck I'll raise a thoughtful, kind-hearted Cubs fan who listens to Merle Haggard.