So there's twin girls who are complete opposites. One girl is a militant pessimist, while her sister's an eternal optimist.
For their birthday, the twins’ mother gives the pessimist every imaginable toy and game—but the optimist only gets a massive pile of horse manure. (Just play along, OK?)
This causes bitter weeping from the pessimist. “Why are you crying?” the mother asks.
“Now I'll have to read all these instructions, and all my friends will be jealous.”
But the optimist twin is dancing for joy on the pile of manure. “And what are YOU so happy about?” the mother asks.
“You got me a pony!”