As children, we see everything as one big story or narrative. We put together apparently unrelated incidents into a story, to make them make sense with respect to each other. It is an important aspect of learning, because children learn cause and effect that way the best. Which is why everything that has to be taught to children, whether morals (Aesop's fables) or relationships (fairy tales) or language (like Kipling's just-so stories) is best taught through stories.
As we grow into adults, we transit (not easily) from narrative to abstract thinking, when we take unrelated events to be,well, unrelated. This learning is not perfect. We fail to see the narrative sometimes when it is there (like stock market crashes), sometimes we see a narrative when there is none (CIA conspiracies).
Writers are in that sense children still - they see and put together narratives. After all, the cleverest stories happen when strange, seemingly unrelated items are deftly woven into something that shocks or delights.