Alzheimer's Repetition

Listen up, buttercup. This joke is about Alzheimer's, which is a disease that causes memory loss. The joke itself doesn't have a traditional punchline; instead, the repetition of the question, "Wanna hear a joke about Alzheimer's?", mimics the short-term memory problems experienced by someone with the condition. The joke's structure reflects the disease. The author's probably still trying to figure out where the punchline is, just like you, little genius.