A couple went to the psychiatrist with their twins, as they seemed to be completely opposite. The doctor noted that one was a Pessimist and one was an optimist.

He put the pessimist in a room filled with new toys. He then, put the optimist in a room full of horse poop.

After a period of time, they looked into the pessimist's room and he was stepping on and breaking all the toys, saying, "I don't like these....none of them!"

They went to the optimist's room that was full of manure, about chest deep and found the little boy yelling, "Whee! Whee!", and throwing handfuls of manure up in the air.

They asked him why he was doing that and he replied, "With all this horse poop in here, there's bound to be a pony somewhere!"