Since we've been home with our son, we seem to notice lots of other adopted children. Our backyard neighbors adopted both of their daughters (and no, we didn't know that before). Lexi's tablemate at school and his brother are adopted. A woman at church adopted her daughter ten years ago. Many people we have met out and about are adopted or have adopted.
So, I think it is a lot like when you buy a new car and then you see that same model of car all over the place. The cars where there all along. Our focus has just shifted and we now see all of the cars that are just like ours. Or in this case, we see so many parents and children blessed with the miracle of adoption.