Why does bringing another baby into my house petrify me?

So if having two kids isn't so bad, why does having a third one kind of weird me out? I've been thinking a lot about this one. A big part of my brain can't fathom loving anyone other kids like Micah and Mackenna. You would think the fact that I've made the transition before from not loving a baby, to meeting two babies, getting to know them, and falling crazy in love with them would make this idea of loving another one not seem so alien-like. But it doesn't. In fact, I think I decided (while I was scrubbing the milk out of the sippy cups), that it actually makes this idea seem even weirder. You see, before, when I was childless and longing to be a mother, I didn't really understand what a mother's obsession would really be like. Oh, I thought I did, and I really did to some extent, but not fully. I actually thought that I wouldn't love my kids as much I loved some of the other darlings in my life. Oh my - was I wrong. So, then, I would see a baby or a toddler and think how cute they were and I could imagine myself bringing them into my home and loving them. Because I thought I already loved them. But now, I see a different baby or toddler and I can't imagine bringing something like them into my home to love. They seem strange and alienlike to me. I enjoy them, I like them, and some of them I love - but they are not Micah and Mackenna - and they don't fill my heart with obsession. I think this is why the thought of bringing a third stranger into my home - Curt, Laura, Micah, and Mackenna's home - feels really weird. In my head I know I will fall obsessively in love with any child God brings into our home, however he does it. But in my heart, the idea just seems off. Like ET coming to live with us - an ET that comes with a lot of mess and crusty milk in sippy cups.