Movies often use a range of tropes and devices to set up the story with their opening scenes. From foreshadowing to flashbacks, the beginning of a film usually sets the tone for the entire movie. As a result of this, many filmmakers tie the beginning of the film directly into the conclusion, with some movies going as far as to simply have the beginning of their movie be the final scene.
Source：https://www.cbr.com/movie-endings-mirror-opening/
