A rabbit walks into a grocery store. He bangs his paws on the counter and yells “a pound of carrots!”

The shopkeeper says “I’ll get you the carrots, but please don’t bang your paws on the counter”.
The rabbit takes the carrots and leaves.

The next day he comes back and again bangs his paws on the counter and yells “a pound of carrots!”

This time the shopkeeper is more annoyed. “I’ll get you the carrots,” he says, “but do not bang your paws on the counter. You are leaving scratch marks.”

The rabbit takes the carrots and leaves.

The next day he comes back and again bangs his paws on the counter and yells “a pound of carrots!”

Now the shopkeeper is mad. “Listen,” he says. “I’ll get you the carrots, but if you do that one more time I’m going to nail your paws to the counter!”
The rabbit takes the carrots and leaves.

The next day he comes back. This time, he politely asks “do you have nails?”

“This is a grocery store, not a hardware store” the shopkeeper replies. “Why would we sell nails?”

“In that case,” says the rabbit while banging his paws on the counter, “a pound of carrots!”