It's Elementary, My Dear Watson

"As you analyze works for ideas, it is important to avoid the trap of confusing ideas and actions" (121).  

I think this is a basic idea that readers learn at a relatively young age.  It is the difference between retelling the plot of a story or explaining what the author intends for the reader to take away from the tale.  I have yet to take an elementary education classes, but I'm going to take a guess that children begin to make this distinction during the same time that they are able to understand Aesop's Fables.  Every single fable is written to teach a lesson.  If the child is able to distinguish the moral from the story without simply retelling the tale, they can distinguish the difference between ideas and actions.