Sorry to contradict you bernado but the idea of the 'myth' is a lot more complex.
A myth (in the true sense of the word) is based in fact as much as it is in fiction. A myth is often based on a universal truth, something that the group of people who perpetuate the myth believe is true or want to believe is true, that usually reinforces the status quo or undermines it.
Wartime is a good example of when myths arise and are perpetuated in order that public morale is maintained. In British history for example the evacuation at Dunkirk in WW2, is based in historical fact, but through propaganda and popular misconception it has gone from being a humilitating defeat and transformed in to a glorious and dignified retreat.
The facts are there in history but the myth has turned it into something else.
The writers of an individual culture's history are influenced, either knowingly or unknowingly, by that culture's myths and therefore dictate how that history is both written and consumed.
I wrote a 30 000 word dissertation on the idea of myth so its difficult to squeeze it into this post.
So therefore just think of history as bread, butter and a toaster, and think as toast as a myth.