I had a clever friend in primary school who figured out how to manipulate his parents based on their desire to maintain his child-like belief in things like the tooth fairy and Santa. He made up something he called the Wattle Fairy who, so he said, would give you a present if you left a wattle flower by your bed at night. He told me about this and I tried it, then was deeply disappointed the next morning to find that the wattle fairy had not left me a gift. I cried to my parents about it who got very awkward suddenly. When I told my friend it didn't work, he said of course it didn't, because you have to tell your parents beforehand. I didn't get it even then. Does that make me a dim kid or just gullible?
Mokalus of Borg
PS - I've always assumed the former.
PPS - Disappointment is shaped like a wilted wattle flower.