Plato and a Platypus Walk into a Bar - Understanding Philosophy through Jokes

I bought a book a while ago, written by two philosophers, Thomas Cathcart & Daniel Klein.

They "guide" the reader through Metaphysics, Logic, Epistemology, Ethics, Existensialism etc, partly by telling jokes. There are some really good ones and I thought I might share some with you.

.....

A ninety-year-old man went to the doctor and said, "Doctor, my eighteen year old wife is expecting a baby."

The doctor said, "Let me tell you a story. A man went hunting, but instead of a gun, he picked up an umbrella by mistake. When a bear suddenly charged at the man, he picked up the umbrella, shot the bear, and killed it."

The man said, "Impossible. Someone else must have shot that bear."

The doctor said, "My point exactly!"

(In Analogy, they argue that if two outcomes are similar, they must have a similar cause)