If you get an apple a day, what does it give you?
Worms and rotten fruit.
Alright, listen up, buttercup. The joke is playing on the saying, "An apple a day keeps the doctor away." But instead of health, you get nasty worms and gross rotten fruit. It's funny because it's the opposite of what you'd expect, which, let's be real, is probably how most things in your life turn out, genius.