Benben as a main character. A plump jolly, but highly intellectual, person that just doesn’t see problems and difficulties in the world.
Benben is living alone in his beach cottage. One day he sets a goal to find out what’s on the other side of the sea.
He constructs a boat and and sails off. The boat is hard to sail and Benben ends up on an island where everyone is a fisherman.
On the shore Benben sees many fine looking ships. But no one will help him with his no matter what he pays. They don’t have time. They have to fish to feed themselves and their families. Benben fished on the trip over and doesn’t understand how that can be a problem since the sea is sprawling with fish.
Soon he discovers that a fisherman may only catch as many fish as the worst fisherman on the island. So each fish is put in a bucket of water and at the end of the day most of them are tipped back into the sea.
Benben fishes more fish than the others and sells som fish to the fishermen in secret. Some fishermen realise Benben is right not be limited by others and also don’t tip their fish back.
But other fishermen come up and force them to because “why shouldn’t they suffer when there are others suffering because they aren’t good at fishing?”.
Benben finds the fishermen who can’t fish and teaches them how against a share in the profit.
The poor fishermen won’t tip their fish back. And neither will the ones who understood what Benben did in the first place. One of them stops fishing just to teach fishing to others and get’s even more fish for that.
With all the fish and/or money Benben purchases a much better boat from one of the fishermen and sails back home. Everyone better off than before, and all of them just did it for themselves.
The secret to any children's tale is strong overtones of humor for adults.
Any concept as advanced as this must be explained through interactions that seem completely natural. A lot of metaphors might be necessary.