Brainstorming: children's stories



So I have a three-year old kid, and will usually read or tell him a bedtime story.

That is a nice opportunity to introduce new concepts, but my capacity for improvisation is limited, especially towards the end of the day. So I'm asking the good people on LessWrong for ideas. How would you wrap various lesswrongish ideas in a short story a little kid would pay attention to?

I'm mostly interested in the aspects of "practical rationality" that aren't going to be taught at school or in children's books or children's TV shows - so things like Sunk Costs, taking the outside view, wondering which side is true instead of arguing for a side, etc.

Pointers to outside sources of such stories are welcome too!

Edit: actually, if you want to share ideas of games or activities of the same kind, go ahead! :)