Read a book of myths, legends and/or folk-tales of your country or culture and see if you can find some familiar stories. Think about how these stories have influenced the literary heritage of your country or culture.
On a related note - it's fun to see how modern authors have spun their own versions of the old yarns. A fantasy novel that I read some years ago was, for example, a great modern version of the Sleeping Beauty* myth, and many romances are twists on one or another of the happily-ever-after myths (e.g. Beauty and the Beast, Cinderella, Sleeping Beauty). Another example is that all the names of the dwarves in JRR Tolkien's books and some of the names of other characters come straight out of Nordic mythology, and many of the stories he tells have a basis in myths or folk-tales. And of course one shouldn't forget all the novels based on the legend of King Arthur and the Knights of the Round Table.
*Enchantment by Orson Scott Card