Source: Floating around the internet
A young man shopping in a supermarket noticed a little old lady following him around. If he stopped, she stopped. Furthermore she kept staring at him.
She finally overtook him at the checkout, And she turned to him and said, "I hope I haven't made you feel ill at ease; it's just that you look so much like my late son."
He answered, "That's okay."
"I know it's silly, but if you'd call out "Goodbye, Mom" as I leave the store, It would make me feel so happy."
She then went through the checkout, And as she was on her way out of the store, The man called out, "Goodbye, Mom."
The little old lady waved, and smiled back at him.
Pleased that he had brought a little sunshine Into someone's day, he went to pay for his groceries.
"That comes to $121.85," said the clerk.
"How come so much ... I only bought 5 items.."
The clerk replied, "Yeah, but your Mother said that you'd be paying for her things, too."