Creation stories are common in all cultures. As it happens that most if not all contradict each other on the details and means of creation, they can't all be true, but all of them can be false.
Given that most if not all ancient creation stories have no evidence to support them and they contradict each other, they are called creation myths.
This in not because I say so, or because that is what I believe, but how things are....which is very easy to check.
