I mean that when you see a literary canon listed, or a writeup of an artistic progression, it looks very like history writing a story, but has actually been constructed at all because of interest in the work at the end. So the progression may be true, but its selection is heavily biased and makes history look like a bunch of stories. In practice, everyone is just trying to write a good one this time out, and artists steal furiously from every possible source they can, whether it fits a marketable story or not; real life is messy and doesn't have to make sense as a story.