I'll admit it. This becoming a parent thing scares me a bit.
More than a bit.
First, I've got the general "will I be a good parent?" worries. Will I raise a pscyhopath? Will I horribly scar my child through incompetence or careless malice? Will I ever get over being grossed out by diapers? Will I ever be able to warm up to something that can't talk about philosophy, or politics, or even Lost for a decade or more? Will the fact that Melissa and I are atheists, or have tattoos, or are pretty lefty, or etc. put our kid in an awkward position in an increasingly conservative U.S.? Did we do the right thing by moving to Baltimore, or did we condemn our kid to a childhood of crime, crummy schools, and mercury in their crabs? Speaking of schools, what will/should we do about their education (I'm sure I'll be speaking about education at length here)?
Second, I have to admit to more selfish, personal, how will this affect my life worries. It's not exactly admirable, but I worry that, now that I have opportunity to travel (both for my jobs and because we have more money now), having a kid will make that hard, especially if I want to travel somewhere more out of the way or be gone for an extended period. Already, between the commute, work at home, etc. etc. Melissa and I need to plan ahead to get out of the house for anything more strenuous than dinner or a movie - when will I get to go to awesome shows and rock out (I remind myself that I don't do that that much now, which is less than comforting)? The consensus, even from reading accounts of "alternative" parents is that, yes, having a kid means you don't get out much for the next 18 years or so.
None of this makes me not want to have a kid. They're just worries and apprehensions that I need to manage. I think, especially for the selfish ones, it's a lot of "you're 30, you have a mortgage, and NOW YOU'RE HAVING A KID. YOU ARE OFFICIALLY OLD." Which is irrational but, I think, probably fairly normal.