That night, the father found the pessimist surrounded by his gifts, crying.
"What's wrong?" the father asked.
"I have a ton of game manuals to read...I need batteries...and my toys will all eventually get broken!" sobbed the pessimist.
Passing the optimist's room, the father found him dancing for joy around the pile of manure.
"Why are you so happy?" he asked. The optimist shouted, "There's got to be a pony in here somewhere!"