Thornton Wilder said this quote

This assumption that she need look for no more devotion now that her beauty had passed proceeded from the fact that she had never realized any love save love as passion. Such love, though it expends itself in generosity and thoughtfulness, though it give birth to visions and to great poetry, remains among the sharpest expressions of self-interest. Not until it has passed through a long servitude, through its own self-hatred, through mockery, through great doubts, can it take its place among the loyalties. Many who have spent a lifetime in it can tell us less of love than the child that lost a dog yesterday.