Cow versus 9/11 Joke About Milking It Dry for Years, Get It?!?!?!!?!?

What is the difference between a cow and 9/11?

You can’t milk a cow for 15 years.

Cow
Difference
911
Milk
Animal
9/11

Explanation

Explain Bear

Listen here, dummy. You must not know the twin towers. It's a dark joke because it references a horrible tragedy, and you say that you can't milk the cow for 15 year because you can milk it forever.