The Truffle
Fritz and Frank were friends. Fritz had a pig named Donut, and he claimed that Donut was a truffle hunter, but Frank was not so sure.
One day, Fritz, Frank and the pig were walking through the forest, when the pig got excited. “Donut,” said Fritz, “seek the treasure!” So the excited little pig waddled off and began snuffling and digging. Soon he uncovered a dark little lump of something vaguely brown in shape, and Fritz proudly swooped in and scooped it up.
“Are you sure this is a truffle?” asked Frank.
“Of course it is,” said Fritz.
“How can we know for sure?” Frank mused.
“Well,” said Fritz, “I suppose we could wash the dirt off of it.”
“No,” said Frank, “better to leave it as it is. If you wash it, and it really is a truffle, well, fine, we'll have to eat it right away, but that's fine. However, if it's really just a piece of shit, washing it would cause it to dissolve away, and then we'd have nothing.”
“Hmm,” said Fritz. “Maybe you're right. Better to leave it as it is, and then we can eat it later.” Whereupon Fritz dropped the little lump into his traveling pouch, and the three of them wandered on through the forest.