So... at the risk of performing thread necromancy, I wanted to put this here.
As I and many others have posted, things happening to your children is frightening, but nightmares are inspirational... so...
Your child falls and obviously cuts / hurts themselves and is crying on the ground. You pick them up to comfort them. You see that they have a small wound on their face. And then a fly comes out of it, slowly the thing in your arms starts to crumble, it wasn't your child, your child is missing and you don't even know how long this thing had taken their place. Did you even have a child before? your not sure anymore... but you feel in your heart of hearts you do...
Changeling the lost is pretty messed up.