Maybe I'm simplifying and applying a template to the "happy ending" cliche.
Once you read this, you'll start seeing that every popular movie today follows this guide, almost precisely to-the-minute. Book says "by page X of screenplay, Y should happen" and you'll see that it does.
The original pattern had the Shaman travel into the world of the supernatural to complete a kind of quest to solve a problem back home. In the Western world, the "supernatural realm" stopped catching on after a while, so we got first the Hero's Journey (vice Campbell) and the modern version of that myth, the MIH/BMG story where the protagonist gets into trouble and out again, possibly while staying in the same town all along.
[1] https://sites.google.com/a/bc.edu/healing-our-world-shaman-t...
"A hero ventures forth from the world of common day into a region of supernatural wonder: fabulous forces are there encountered and a decisive victory is won: the hero comes back from this mysterious adventure with the power to bestow boons on his fellow man."