Actually it DOES happen sometimes. I know of a few young people that are caring for, or planning to care for older loved ones. But I doubt they would be doing it if they did not have an older example to learn from and follow. If someone taught them and exampled that kind of thing, the odds are better that they too will follow suit. I was a selfish rotten kid, but when there is need, people change and do what needs doing.
As an example, my grandparents took care of their parents, and my parents took care of their parents, and low and behold my wife and I are involved in taking care of our parents right now. And my adult son and daughter have seen all this, and at least of this writing, I feel that they will be there for my wife and I in our time of need. My family heritage is not without plenty of discord and disfunction. We dont all get along all the time, nor are any of us particularly wonderful people, but exampled behavior is a strong thing. When it was our time to step up, we just started doing what was needed. And surprises of surprises, it kinda feels good to do it. 15 years ago, I never would have believed I would be writing this though...