“It kills you to see them grow up. But I guess it would kill you quicker if they didn’t.”

This sentence will get you thinking. Parents always loves their children, even if the kid is irritating. They always fear the day when the children is old enough to move out of the house. However, if their kid died or had Down syndrome or something else, I think something like that would be even worse then them leaving. Because if they just moved out, they could still visit you. If they died, they would never leave their parents, because they would always be hunting their parents as ghosts in their head.  People with Down syndrome, need so much help that their parents would always be with them until the day they die! That is what I think the sentence is saying.

what do you think the meaning of the sentence is?