Having children is certainly a scary thing that no one is ever ready for.
But, as much as I value my freedom etc., there is nothing I want more than to get to raise some kids to be awesome people to carry on when I am gone. If I don't have a son my last name dies with me...
I think my future kids will be a positive influence on the world. I want who I am (my genes) to play a role in what the future of the human race looks like.
I'm selfish enough as it is, I can't wait to find a woman I love more than I love me, and to then have kids I'd gladly lay down my life for. I think that will fulfill me in a way that all the traveling, consumption, fun etc... never could.
I don't really worry about screwing my future kids up because my folks did a pretty good job with me and my sis.
But then again different strokes for different folks.