Try this summary of common sense on spark notes it helped me when i had to do similar questions http://www.sparknotes.com/lit/commonsense/summary.html
Answer:
The reader knows that the Shepherd boy was a foolish person due to his actions. Instead of crying wolf in a real scenario he decided to do it as a joke for being bored. Not only was he very foolish but he was also a liar who was affected by his own foolish actions. The moral of the story is, think before you act.
