Storytelling is inherently dangerous. Consider a traumatic event in your life. Think about how you experienced it. Now think about how you told it to someone a year later. Now think about how you told it for the hundredth time. It’s not the same thing. Most people think perspective is a good thing: you can figure out characters arcs, you can apply a moral, you can tell it with understanding and context. But this perspective is a misrepresentation: it’s a reconstruction with meaning, and as such bears little resemblance to the event.
The other thing that happens is adjustment. You find out which part of the story works, which part to embellish, which to jettison. You fashion it. Your goal is to be entertaining. This is true for a story told at a dinner party, and it’s true for stories told through movies. Don’t let anyone tell you what a story is, what it needs to include. As an experiment, write a non-story. It will have a chance of being different.