Spend enough time taking care of children and it becomes an inescapable part of your psyche. It makes it way into your dreams in sometimes overt, sometimes subtle ways. Last month I dreamed that Clara was trying to get Kate to swim in a pond where a shark was swimming. I'm no psychoanalyst but I think such dreams show I have some pretty deep fears about the safety of my children. Even when your children are at school or you have a babysitter you are not free from what I have found is the most common form of parental paranoia: Phantom Cry Syndrome. Randomly, out of nowhere, you will hear your child's cry.
I just made PCS up. But the next time it happens to you, you'll know what to call it.