I certainly wouldn't compare the rewards of watching one's...

I certainly wouldn't compare the rewards of watching one's children grow and mature with that of money piling up at the box office. Both are pleasant, but to varying degrees. As the old saying goes, you can't take an audience home with you. You can't depend on the loyalty of fans, who, after all is said and done, are just faceless people one seldom sees. And few stars have their fans forever. But a child is forever. That bond and relationship is timeless and doesn't depend on your looks, age or popularity at the moment.