One never laughes alone. When two understand each other, they laughes. During laughing, the world comes to be like timeless. I think that it's most greateful for humans to live with laughing forever. May be, rather than living alone, it's more healthy to live and laugh with your believable company. In order to make a friendship of laughing each other, you need to construct a relationship of mutual trust. Trust comes into being from a sacrifice. If you want to please others very much, you don't regard yourself as a sacrifice and can come to be sincere naturally. Unless a relationship contains trust, the relationship never bears a good smile or a good laughter. Parents teach smiling to their baby at first. The baby grews older. At that time, whether the one finds a good smile or a good laughter, or not, represents the growth in human of the one. A fortune-teller often says that the one who can smile lovely is able to get happy. If the happiness means the one's growth in human, it can be regarded as a matter of course. I think that a good smile is inavailable easily, and it is build on a relationship of mutual trust and sincerity. Have you noticed the fact that the one who wants earnestly to please others smiles beautifully always at first? I think the one who wants earnestly to please others can get the feeling of a real pleasure.

Why the God gave laughter only to human being? Maybe, it's because the God wants to enjoy together with humans laughing.