jellyfish: lesson on being flexible, going with the flow, being adaptable in situations you don't have control over: create jelly fish out of coffee filters, water, and markers. hole-punch the edge and tie yarn through it, and then attach notes on the tentacles that describe situations you should "go with the flow."
Flow is something that happens once mastery occurs. It's having an equal balance between being challenged and then matching it with ones own abilities. In teaching, it's matching up more difficult material for students with their learning abilities.