A Dutchman, a German and a Belgian are planning to walk in the desert. The Dutchman says: "I'll bring an umbrella for the shade when it gets too hot." The German says: "I'll bring some sunglasses. This sun can really destroy your eyes!" The Belgian remains silent. Next day, the Dutchman and the German are astonished. "What's that?" they both shout. The Belgian answers: "It's a car door. Now I can open the window when it gets hot..."