The chosen child will grow to a point in which they either realize the parent is a narcissist that is not capable of providing the love and acceptance the child has been seeking their entire lives OR will never wake up and realize the abuse that has been imposed on them. If the child takes the latter route, the child will live a stunted life; they will propagate the abuse they endured onto their own children.
For the child that realizes his parent is, in fact, a narcissist, there are three choices. Choice number one is to continue to cater to the narcissist and allow the guilt the narcissist impels upon them to push them in directions they do not wish to go and to do things they do not wish to do. To do this is to basically give up your life for a worthless cause. Nothing you ever do will ever be enough. They will use you forever and ruin your life. They will tell you nice things to get what they want (admiration, caring, help, etc.), but- to them, you’re only as good as the thing you’re doing for them at that moment in time (or about to do for them). For them, NOTHING YOU DO IS EVER ENOUGH- nor is it ever GOOD ENOUGH!