I second that point about folklore and it's also true for science-fiction. Authors do so much research, not all of it goes up on the page and sometimes even ignored completely because it doesn't make for a good story but it definitely happens. I was 12 when I first came upon the concept of tachyon particles in a pre-teen audience sci-fi book. Tachyon particlea are still totally theoretical but I spent a summer learning what I was able about the laws of relativity, causality paradoxes and M-theory. That same book series also taught me about history when the main characters would travel to points in time and introduced me to the War of the Roses and Lost Colony of Roanoke and I spent time looking into that as well. Then years later I watched Game of Thrones for the first time and saw all of the connections between that world and the War of the Roses (York -> Stark, Lancaster-> Lannister, Bran and Rickon Stark disappearing one night like Edward the Fifth and Richard of York, Tyrion and Richard the Third, two disfigured nobles who are accused of murdering their kin for power, Sansa and Elizabeth Woodville, eldest daughters offered up for political marriages). No creations exist in a bubble, everything is influenced by something and it's one of the absolutely beautiful things about art.