"Being A Truck Driver" joke

The Boy Who Wanted to Be a Truck Driver
One day, a little boy goes into the candy shop and orders five pounds of "m-n-m's",.
The lady at the counter asked him "Don't you mean five bags?"
He said "No, i want five pounds."
She was reluctant, but measured them out, put them in a bag and handed them to the little boy. He paid for them, and went outside and sat on the curb.
He ate a few m-n-m's, and a cat walks by.
He picks up the cat and takes a big bite out of it.
He moves a little further down the curb, and does it all over again.
After the little boy did this about 15-20 times, the lady in the candy store starts to wonder.
She goes outside and asks the little boy "What in the hell are you doing?"
The little boy gives her this answer "I am learning how to be a truck driver like my daddy. I'm popping pills, eating pussy, and moving' down the line."