How often one hears children wishing they were grown-ups, and old people wishing they were young again. Each age has its pleasures and its pains , and the happiest person is the one who enjoys what each age gives him without wasting his time in useless regrets . Childhood is a time when there are few responsibilities  to make life difficult. If a child has good parents, he is fed, looked after and loved, whatever he may do. It is impossible that he will ever again in his life be given so much without having to do anything in return. What's more, life is always giving new things to the child--- things that have lost their interest for older people because they are too well-known. But a child has his pains: he is not so free to do what he wishes to do; he is repeatedly being told not do something or being punished for what he has wrongly done. When a young man starts to earn his own living, he can no longer expect others to pay for his food, his clothes, and his room, but has to work if he wants to live comfortably. If he spends most of his time playing about in the way he used to as a child, he will go hungry. And if he breaks the laws of society  as he used to break the laws of his parents, he may go to prison. If, however, he worked hard, keeps out of trouble and has good health, he can have the greatest happiness of building up for himself his own position  in society. What is the happiest person according to the passage?
A child who can do whatever he likes. An old person who lives in a comfortable life. A grown-up who no longer expects other to pay for him. A person who never wastes his time in his whole life.