C.S. Lewis agrees.
The modern licence claimed by novelists and short-story writers to use their imaginations as freely as they please prevents students of mythology from realizing that in North-Western Europe, where the post-Classical Greek novel was not in circulation, story-tellers did not invent their plots and characters but continually retold the same traditional tales, extemporizing only when their memory was at fault. Unless religious or social change forced a modification of the plot or a modernization of incident, the audience expected to hear the tales told in the accustomed way. Almost all were explanations of ritual or religious theory, overlaid with history: a body of instruction corresponding with the Hebrew Scriptures and having many elements in common with them.
~Robert Graves, “The White Goddess”