All the experts say don't leave your child without warning them that you are leaving. That is what this verse is all about. In this entire chapter, Jesus had been telling his disciples that he was going to be leaving them but that he would be returning one day for them. It kind of reminds me of a mom leaving her child at the nursery at church or dropping her child off at school. That anxiety. That fear. That worry of being left by their security blanket.
I want Jesus as my security blanket. If I have any fear in my life that is the kind of fear I want it to be... the fear of being separated from my Lord.