You walk through the crowded train. You try to find an almost empty compartment. Finally you reach one that at first glance appears empty. To your disappointment, there is a person sitting at the window. A boy, the same age as you, maybe a few months older. You push the door open and ask the polite question: "Isn't there a seat here?" He smiles kindly and nods to the free bench in front of him. "Sure. Sit down." You sit down opposite him. He seems friendly and there is something calm about him.