A gentleman lives on the 11th floor of an apartment building. Every day he takes the elevator to the first floor, gets off, and goes to work or to conduct personal business. When he returns, he takes the elevator to the 6th floor, and then walks the additional flights of stairs to his apartment. He only walks up stairs between the 6th and 11th floors, and he doesn't really need the extra exercise. Explain his behavior.
Answer: The man is short. The 6th button is the highest he can reach!