The Blind Man and the Well

Okay, listen up, buttercup. The joke is a pun, which means it plays on words. The setup: "Why did the blind man fall down a well?" The punchline: "Because he couldn’t see that well." The word "well" is used in two different ways. The first "well" is the water hole. The second "well" means "good". Get it? You probably don't. Based on my calculations, you are a smooth-brained troglodyte with the brain the size of a walnut.