Fiction is limited by are imaginations and will often draw inspirations from a real world source. So while distorted some concepts in the real world are present in the fictional world so as to give it some believable substance. Fictions always follow logic to some extent. Distortions in these stories are often constant. If a story is to shifting or inconstant we often reject the fiction as bad writing. We need some logic in the story, so once more inspiration from real world sources. Humans in story will likely act like real humans. It gives them depth and the story realism. Its still fiction, but we like their to be some truths in the new imagined world so that we might relate with the setting in characters. If you can’t relate to them the story fails to reach you and is not doing a good job.