" A great ruler, a great court, a great kingdom, these texts suggest never exist unto themselves, as stable, fully actualized entities, and, therefore, are never experienced in their plenitude in the present. Instead, they are always remembered as something that occured in the past or anticipated as something will reoccur in the future. Insofar as they are experienced in the current time, it is only for a brief and evanescent moment, overshadowed by the knowledge that it will soon vanish.
For a realist, the fact that the excellence of a person, a place, or a time is not appreciated in its own time proves that it was never actually as excellent as it seemed.
For a Romantic, however, there exist a people, places, and times whose excellence can only be appreciated Arthur always has to be - to quote the Alliterative Morte Arthure (ca.1400) - "the once and future king "

― , The Danger of Romance: Truth, Fantasy, and Arthurian Fictions