Is this the best joke ever?

Usually, I try to say something original, but today I am dumb-struck having just read a super good joke that I now I wish to share with everyone:

A guy spots a sign outside a house that reads “Talking Dog for Sale.” Intrigued, he walks in.

“So what have you done with your life?” he asks the dog.

“I’ve led a very full life,” says the dog. “I lived in the Alps rescuing avalanche victims. Then I served my country in Iraq. And now I spend my days reading to the residents of a retirement home.”

The guy is flabbergasted. He asks the dog’s owner, “Why on earth would you want to get rid of an incredible dog like that?”

The owner says, “Because he’s a liar! He never did any of that!”