Riddle: A man lived on the 20th floor of a block of apartments. Everyday he would enter the elevator and go down to the ground floor and go to work. When he comes back, if it is raining, then he would go straight to the 20th floor in the elevator, but if it is sunny, then he would only go to the 10th floor and walk the stairs for the rest of the way. Why does he do it?
Answer: The man is a dwarf and when it is raining he can reach the 20th button on the elevator with his umbrella, but if it is sunny he can only reach the 10th button.