Mostly, children grow up thinking all the attention their parents give them is part of the duty of the parents. They think, "Perhaps if I am able, I shall pay it back." The ancient idea was different. For instance, the Prophet Mohammed taught his disciples that the greatest debt everyone has to pay was to his or her mother. If one wished one's sins to be forgiven, one must act in life so that before passing from this earth one's mother would say, "I have forgiven you the debt." There was nothing -- money or service -- that a person should say, "I have paid." No, one's mother must say, "I have forgiven you that debt." What does it teach? It teaches the value of unselfish love which is above all earthly passion.