the most powerful thing in the world

All about love. The little girl is so adorable that every time she appears you would not want to move your eyes off her. Amazingly beautiful, and so smart, so sweet. Her father so kind. Like father, like daughter.
It is the kind of movie that makes you pour tears.
As to education, I'd say I agree that the best education in the world is to teach you to love, of course in the way of love. Just as Lucy says, "all I want is Das, all I want is love." It helps build personality, enables you to be passionate, to be tough. And obviously it is the source of happiness.