Lesson on the fly

Just a little while ago, D.6 and S.2 got into with each other.  There was screaming and pulling and sitting.  No blood, though.
  After they received a painful reminder that fighting with each other is not appropriate for siblings who should be taking care of each other, I talked to them with a story.  At first, I did not know what my story was going to be.  I just started it.  I did not know where it would be going or if they would even understand it.  Here's how it went:
   "There were two brothers (or a brother and a sister).  They were each told to plant something.  The older brother was told to plant some vegetables, and the younger brother was told to plant some flowers.  They got to fighting about it.  The older brother complained, 'Why does he always get to plant fun stuff? and I have to plant boring things.' The younger brother complained, 'Why does he always get to plant important things?' Well, they fought about it so much that neither one planted anything.  (Here I asked D.6 "What do you think happened?"  She says, "They got in trouble.")  Since nothing happened to get planted, nothing grew.  No good food to eat; nothing pretty to look at."
    So the moral of the story on the fly off the top  of my head, is that brothers have to get along to provide for others.
  It may not be the best story ever, but I was amazed that I just looked into their pitiful faces and came out with that.  Hmm...  Thoughts??