I have a few thoughts on it:
1) Any child I adopt WILL be my kid. The phrase you're looking for is "Don't you wish You could have your own biological children?" I will treat any children in my own as if they were my biological children because they will be important parts of my life, regardless of DNA.
2) Of course I do wish I could have my own biological children. And I'm not completely cutting out that possibility. Is it my top priority right now? No. But just because I go through adoption and all those heartaches and woes doesn't mean I cannot ever have biological children.
I think some people get hung up on normalcy... just because a child isn't my own biological creation doesn't mean that the child is not mine.