WHEN I GROW UP.....

A fireman is at the station house working outside on the fire truck when he notices a little boy next door. The little boy is in a little red wagon with little ladders hung off the side. He is wearing a fireman's hat and has the wagon tied to a dog.
The fireman says "Hey little boy. What are you doing?"
The little boy says "I'm pretending to be a fireman and this is my fire truck!"
The fireman walks over to take a closer look. "Little boy that sure is a nice fire truck!" the fireman says.
"Thanks mister", says the little boy.
The fireman looks a little closer and notices the little boy has tied the dog to the wagon by its testicles. "Little boy", says the fireman, "I don't want to tell you how to run your fire truck, but if you were to tie that rope around the dog's neck I think you could go faster."
The little boy says, "You're probably right mister, but then I wouldn't have a siren!"