Firetruck Siren

One day a man is walking down the street, when he notices a
young boy in a wagon fixed up to look like a firetruck. The man
also notices that the wagon is being pulled by a dog with a rope
attached to his nards! The dog is, of course, howling like a
banshee, and inching along ever so slowly. The man thinks for a
moment, then approaches the boy and says: "You know, son, the
dog would probably pull you faster if you had the rope attached
to his leash." The boy looks up at the man and says: "Well,
yeah, maybe, but then I wouldn't have this really cool siren!"