Once upon a time there was a little boy who became very ill. He had to spend all day in bed, unable to move. Because other children weren't allowed to come near him, he suffered greatly, and spent his days feeling sad and blue. There wasn't much he could do except look out of the window. Time passed, and his feeling of despair just grew. Until one day he saw a strange shape in the window. It was a penguin eating a sausage sandwich. The penguin squeezed in through the open window, said "Good afternoon" To the boy, turned around, and left again. Of course, the boy was very surprised. He was still trying to work out what had happened, when outside his window he saw a monkey in a nappy, busy blowing up a balloon. At first the boy asked himself what that could possibly be, but after a while, as more and more crazy-looking characters appeared out the window, he burst out laughing and found it hard to stop. Anyone wanting to stop laughing would never be helped by seeing a pig playing a tambourine, an elephant jumping on a trampoline, or a dog wearing a pair of glasses and talking about nothing except politics. The little boy didn't tell anyone about this because who would have believed him? Even so, those strange characters ended up putting joy back in his heart, and in his body. Before long, his health had improved so much that he was able to go back to school again. There he got to talk to his friends, and tell them all the strange things he had seen. While he was talking to his best friend he saw something sticking out of his friend's school bag. The boy asked his friend what it was, and he was so insistent that finally his friend had to show him what was in the bag: there, inside, were all the fancy-dress suits and disguises that his best friend had been using to try to cheer the little boy up! And from that day on, the little boy always did his best to make sure that no one felt sad and alone. 
Friends are for cheering you up in your worst moments. 