Plot twists exploit cognitive biases. Audiences assume the most obvious interpretation is correct. They trust the narrator. They accept genre conventions. A skilled filmmaker exploits these assumptions, building a logical alternate explanation that the audience's own mental shortcuts prevent them from seeing.

The Usual Suspects, Memento, and Parasite all use the audience's assumptions as weapons against them. The twist is not in the film. It is in the gap between what the film shows and what the audience chooses to believe — revealing that the audience was complicit in their own deception.