Rover the Brick

A policeman is walking down the road when he sees a man with a brick tied to a
dog leash. He decides to go and humor him. He walks up to the man and says,
''Hello, sir, I like your dog!''
The man looks at the brick, then the policeman, and says, ''It's not a dog,
it's a brick.''
The policeman replies, ''Oh, sorry, I thought you were a bit mad,'' and walks
off rather puzzled.
As the policeman goes out of sight, the man turns to the brick and says,
''That fooled him, didn't it Rover?''