A father had two little sons, one of whom was an eternal optimist, while the other was a perpetual pessimist. One Christmas he decided try to temper both of their proclivities: in addition to their standard gifts, he told them they'd each get something "chosen especially for you!" His plan was to give the pessimist every toy and game he could possibly desire, while the optimist would be directed to the basement filled with manure.
On Christmas, after the normal presents were opened, the father sent the optimist to the cellar, while leading the pessimist to the room filled with presents. After the pessimist opened all the gifts, he turned to his father with a sad face and said: "How can I possibly use all these? The TV will wear out, the Nintendo will get smashed, and all the other toys will be broken!" After a few minutes of listening to such woe, the father remembered his optimistic son, and ran to the basement steps.
There in the basement was his other son, swimming through the manure with a gleeful smile. The father asked him why he was so happy, to which the boy exclaimed "With this much manure, there must be a pony in here somewhere!"