I love my kids.
I wouldn't trade the experience of raising kids away for all the money in the world.
That said, you lose a bit of yourself when you have children. You can't go out very often anymore. No concerts, no adult-themed movies, no whimsical excursions to Vegas, no fancy schmancy restaurants, no bar hopping, no getting stoned until you feel your face melting away, and no drop everything and go where you want. Sure, there's babysitting, and Lynn and I are very lucky that we both have parents that are more than willing to watch the kids on occasion so we can go out. Nonetheless, the whole time you're out when your kids are young you can't fully enjoy the fancy schmancy restaurant because you're worried if the kids are okay and you miss them if you're gone more than 3 hours.
Not only that, but the kids become your life and almost all that you know. Conversations with friends are dominated with the wonderful things your children do. When they're babies you even talk about their bowel movements to friends who also have infants. As they get older, their achievements are bally-hooed to whomever will listen to you.
Naturally, you begin to lose touch with friends. You're too busy taking your kids to Karate, swimming lessons, school, camp, or whatever it is that they're busy with and so are your friends as they also have children. My wife and I used to go places all the time with another couple and now that we both have kids, it's next to impossible to even see them twice a year, even if we get the kids together.
Thankfully the internet is here! Over the past few years I've reconnected with some old friends and thru email I'm able to keep in touch. I rarely see any of them on any regular basis. But at least I have some form of adult contact outside of my wife, work and poker group.
Unlike my parents, when my kids are old enough to go off to college or move out I don't think I will have to deal with the "empty nest" syndrome. My parents certainly had the worst of it and even separated for a year shortly after my brother and I moved out. I don't think they knew how to deal with each other when they didn't have the common thread of raising us. Their social skills with adults were diminished to a huge degree and they suddenly had different interests.
As I regain contact with old friends and gain some freedom as my kids get older I feel myself becoming whole again (but different). However, it was good giving up part of myself to create a family, and some parts will never be back. I say good riddance to that.