Riddle: What walks on four legs in the morning, two legs in the afternoon, and three legs in the evening?
Answer: A human. The morning represents the beginning of your life when you crawl, using four "legs." (both hands, and both feet) The afternoon represents the middle of your life when you walk with both of your legs. The evening represents the end of your life when you walk with a cane. (two legs, plus the cane)