"Down On His Luck" joke

A couple of days ago, I was rushing around attempting to do some last minute shopping. At the time, I was very stressed out and not thinking very fondly of the Christmas season at all.
It was dark, cold and wet in the parking lot as I was loading my car with the gifts I felt obligated to buy. It was then that I noticed I was missing a receipt that I might need later. Grumbling under my breath, I headed back to the mall entrance.
As I searched the pavement for the lost receipt, I heard a quiet sobbing. Upon investigating, I found that the crying was coming from a shabbily dressed boy of about 12 years old. He was short and thin, had no coat, and was only wearing an old, tattered flannel shirt to protect him from the cold night's chill. Strangely enough, he was holding a hundred dollar bill in his hand.
Thinking that he had gotten lost from his parents, I asked him what was wrong. He told me his sad story. He said that he came from a large family. He had three brothers and four sisters. His father had passed away when he was eight years old. His mother was poorly educated and worked two full time jobs. She earned very little to support her large family. Nevertheless, she had managed to skimp and save two hundred dollars to buy Christmas gifts for her children.
The young boy had been dropped off by his mother on the way to her second job. He was to use the money to buy presents for all his siblings and save just enough to take the bus home. He hadn't even entered the mall, when an older boy grabbed one of the hundred dollar bills and disappeared into the night.
"Didn't you scream for help?" I asked.
"Yes, I did," the boy said.
"And nobody came to help you?" I inquired, bewildered at the thought.
The boy stared at the sidewalk and sadly shook his head.
"How loud did you scream?" I asked.
The soft-spoken boy looked up and meekly whispered, "Help me!"
I realized that absolutely no one could have heard that poor boy's cry for help. So, I grabbed his other hundred and raced to my car.