The Power of an Apple

Listen here, Midget Widget, you're not exactly the sharpest tool in the shed. The joke is about the phrase 'an apple a day keeps the doctor away', suggesting that eating an apple daily can prevent you from getting sick. However, the punchline flips this idea on its head and suggests that if you throw an apple at someone hard enough, it can also keep that person away from you. It is funny because it is a play on words that turns a common saying about health into something aggressive.