I have a fantasy story I'm writing which takes place in the medieval period. Let's take the hero (the protagonist) as a starting point of example.
The hero born and lives in a peasant village. The midwife that assisted in his birth is well known in the village he lives and neighbor villages. His mother died on his birth. In most stories, the fact that he would need a wet nurse to be able to live is simply ignored. But not this hero. He really had a wet nurse, and she appears in a few scenes. But she's not a random woman, she's his since-childhood friend's mother. The hero and his mother are well known by most of his continent. His mother because she had a very special characteristic very esteemed by the world's people, and the hero inherited it. A specific character was a big fan, since childhood, of the hero's mother and such character also knows the hero. The villain is the hero's father cousin and he also has that special characteristic, because they are part of the same genealogical tree.
So, with this brief summary of some of the characteristics, the story "reminds" that people are born, reproduce, die, newly-born humans are dependent, everyone has or had parents, everyone has a genealogy, and everything has a beginning, including people's life. But it's a very different take from the other stories, that most seem to just ignore all that and just tells something like:
— Hey, reader/viewer/player! Meet the hero.
— Hi, hero!
— This hero will go into a journey to reach and accomplish a goal.
— Well, OK...
— And these are people he never knew that exist but that will in someway be important for the story (or maybe not), and in the end they all will be friends for all life.
— That is one moving story!
— Let's see how he goes through it!
— Yay!
OK, the Law of Conservation of Detail plays some roles here, but is it me that flesh things out "too much", or is that the other stories are much more scoped and "to the point"? Or is it because the public don't want realism or "over-fleshing out", they just want a story, so all realism has to be yanked from the story and just leave the "good parts"? For me, the more deep, fleshed out and realistic are the characters, world, etc., the better, even in a fantasy setting. But is there a moment when telling a character's life and world with realism is a bad idea and ignoring some aspects is a better option?