"Perfect Pet" joke

A man goes into a pet shop and tells the owner that he wants to buy a pet that can do everything. The shop owner suggests a faithful dog.
The man replies, "Come on, a dog?"
The owner says, "Alright, how about a cat?"
The man replies, "No way! A cat can't do everything. I want a pet that can do everything!"
The shop owner thinks for a minute, then says, "I've got it! A centipede!"
The man says, "A centipede? I can't imagine a centipede doing everything, but okay. I'll try a centipede."
He gets the centipede home and says to the centipede, "Clean the kitchen."
Thirty minutes later, he walks into the kitchen and it's immaculate! All the dishes and silverware have been washed, dried, and put away; the countertops cleaned; the appliances sparkling; the floor waxed. He's absolutely amazed.
Then he says to the centipede, "Go clean the living room."
Twenty minutes later, he walks into the living room. The carpet has been vacuumed; the furniture cleaned and dusted; the pillows on the sofa plumped; and the plants watered. The man thinks to himself, "This is the most amazing thing I've ever seen. This really is a pet that can do everything!"
Next he says to the centipede, "Run down to the corner and get me a newspaper."
The centipede walks out the door. Ten minutes later, no centipede. Twenty minutes later, no centipede. Thirty minutes later, no centipede.
By this point, the man is wondering what's going on. So he goes to the front door, opens it, and there's the centipede sitting right outside.
The man says, "Hey! I sent you down to the corner store 45 minutes ago to get me a newspaper. What's the matter?!"
The centipede says, "I'm going! I'm going! I'm just putting on my shoes!"