I've always felt that I never needed my own kids. I'm sure my brother will eventually produce several of them, and I'm completely fine being the crazy childless aunt who babysits them once in a while. I like kids, but I don't often fantasize about having any. I never really did, even growing up.
If I ever decide to raise my own kids, I'll just adopt. I think there's plenty of children in this world that don't have parents and could use a couple loving ones. Again, though, I've never really thought too much about this sort of thing. Maybe a maternal instinct will pop up suddenly in ten years, I don't know.
I guess in some ways, I'm afraid of screwing potential children up. I guess that's a fear all parents have at one point or another. Still, mostly, I just want the next ten years open to explore myself and the world outside. Ten years from now, who knows how I'll feel? Either way, I don't mind if my potential children are not technically my own. My mother keeps pushing me to go to the sperm bank, but I honestly don't care. And that's great if you do, though, it's wonderful that you're taking the step to still eventually have your own children someday. I just never had that drive, and the sperm bank is an expense that I'd rather not shell out for, considering all the other things I need to spend money on just so I, myself, can be happy.