Mr. and Mrs. Peterson were worried about their two boys, Sam and John. So they went to a psychologist to explain their problem. Sam was an incurable pessimist while John saw everything in a bright and enthusiastic light. It was all too much for the Petersons.
The shrink suggested that, with Christmas right around the corner, the couple buy Sam absolutely everything he wanted and more besides. And for John, he suggested a bag of horse shit.
Christmas came and the shrink stopped by the Petersons. Sam opened the door. "Merry Christmas, Sam," said the shrink. "And what did Santa bring you for Christmas?" "Oh," said Sam with a sullen look, "he brought me an X-box and an electric train and a bike and a jet ski ...." John rattled off a laundry list of wonderful things in a very gloomy tone of voice.
Suddenly, skittering around a corner, came a clearly excited John, who crashed into the shrink. "Merry Christmas, John," said the shrink. "And what did you get for Christmas?" "Oh! Oh!" said John, so excited he could barely speak, "I got a pony, but I haven't found him yet!"
No one would mistake a sack of shit for a pony, but I reckon we all forget from time to time.