Hugh Grant, in the movie Nine Months, finds out he's going to be a father and, suddenly, he's dragged into the world of being friends with Tom Arnold and Joan Cusack, two inveterate parents. Since having kids, I no longer go out to lunch with co-workers, opting instead to eat while I work so I can get home sooner. I've traded my backpacking budding and Land Rover compatriots for the fellow parents from the kids' schools. Instead of game nights where cutthroat rounds of Scrabble and Scattergories are fought and won, I stay home to play memory or -- heaven forbid -- Fancy Nancy.

But it's not just parents whose circle of friends shift and change when that bundle of joy comes screaming into the world. Stephanie Powell laments the loss of her last long-time non-parent friend when she finds out her friend is pregnant. "Jodi was my dependable, childless friend," she laments. "And I liked it that way."

I think it must be just as difficult for people to see their friends slipping into a world they don't understand or want to be a part of. I imagine it might even be like seeing a friend finding religion and disappearing more and more into the world of masses and church socials. So too, however, is it a sacrifice for the parents who give up those last minute hikes and happy hours. I no longer stay out late at night playing poker or throw my gear in the car for a spur-of-the-moment backpacking trip; going to the grocery store requires advance planning now.

The difference, though, is that, as parents, we made the choice to change worlds. Our friends who are being left behind got no say in the matter. They certainly have a right to feel left behind, although there's nothing they can do about it, really. There are, however, things we, the parents, can do, both for our childfree friends and ourselves.

There's no reason two parents can't trade off taking "single breaks" -- one parent watches the kids, perhaps on a playdate at the park, while the other parent gets a day or evening of being unencumbered and free. Just make sure that the offer is reciprocal. We do that a lot, although I will ashamedly admit it seems I get time off more often than my wife does.

Another point to remember is that while a newborn doesn't do much, once a kid is walking, there's a lot they can do. Bicycles can be fitted with baby seats. Jogging strollers can handle hiking trails. I've even been backpacking with a baby well under a year old. And while you probably wouldn't want to bring your kids along to a smoke-filled poker room, there's no reason a game night couldn't include a kids table where the little ones play Boggle Jr. or Hi Ho! Cherry-o.