Ever raise a child?
Then one of the things you know, down to your bone marrow, is how much work it is to do this job well. That's true of any child, including a reasonably healthy kid facing all the usual challenges of growing up.
How do you feel about adopting a child? Let's say a child with brain damage, severe physical problems that will require medication for a lifetime, and emotional problems caused by rejection and neglect.
Here's how I feel: Overwhelmed at the very idea.
This is why some children are usually considered unadoptable: Most people feel the way I do. But amazingly, not everybody.