Final answer:
An exemplum is a short anecdote used to illustrate an idea or moral, often engaging the audience from the start. These stories, like Aesop's Fables, typically come with morals and have been used since the Middle Ages. Myths, although similar, are usually grand tales, like Ovid's myth of Narcissus, meant to explain the world or instill values in society.
Step-by-step explanation:
An exemplum is a brief story or anecdote, common in the Middle Ages, told to illustrate an idea or moral. One of the key purposes of an exemplum is to engage readers or listeners from the start, much like an introductory anecdote. These stories often contain morals that highlight the virtues or downfalls of characters within the tale. An example of this is found in Aesop's Fables, which have endured through time to teach lessons such as 'even the smallest animals serve a mighty purpose'. Myths, on the other hand, are a bit different; they are fictional narratives that are typically of epic proportions and are used to explain the world, promote a religion, or imbue a society with values, such as the myth of Narcissus from Ovid's "Metamorphoses".
When creating written content, such as for a personal narrative, it's advisable to scope the story appropriately, focusing on a single event or moment in time to provide a compelling narrative within a limited word count, using techniques like an anecdote or an allegory to add depth and insight.