Mythos

In my version of the universe, I can put all of the weird aspects of my made up world into the book and no reader will ever be bored by it. In the universe as it actually exists, I know that is not so. That is why at least 50% of the mythology and such that I created for my fictional world in Supposedly Epic Book will never make it onto the page, not even in draft one. Why? Because, in my heart of hearts, even I know that most readers won't care.

However, I could not resist including at least some of it into the book. And I'm trying to convince myself it is important. After all, since I am devoting around 500 words to a mythological story, it should probably be entertaining as well as informative.

My MC is traveling to reclaim a stolen item, and when asked why it was stolen, she replied, "Well, they don't like us very much." When asked to explain that, she tells the story she was told as a child -- a myth. I want her to question the real cause of the wars, which none of them know. If she doesn't question the war, then no one's motivations are going to have many levels.

Does including the myths slow the story down too much? Gosh, I hope not. Otherwise, I'm going to have to find a way to make it go faster and more interesting while keeping it in the story. It's basically back back story. Bad form, maybe, but I want to keep it in. I loved mythology as a kid, so I have no problem reading it in a book. Others, I know, are not the same.

Does brief storytelling make things too slow? Is it too obvious as back story?

How much myth do you use in your writing? Do you ever make up the mythology for your characters?