In a zombie apocalypse movie, nobody's ever seen a zombie movie. Or in an alien invasion movie, nobody has ever seen an alien invasion movie, like 'Independence Day.'

In this quote, Ernest Cline discusses a common narrative trope in films, especially in the zombie apocalypse and alien invasion genres. He points out that in these types of movies, the characters are often unaware of the typical scenarios depicted in other genre films, like zombie movies or alien invasion movies such as 'Independence Day'. This creates an interesting disconnect, where characters react to extreme situations without the advantage of prior knowledge from movies or media, despite the fact that they are living through similar events.

Cline's statement highlights how these genres often set up their narratives as if the world depicted within the film has never experienced fictional or pop culture representations of the same events. This creates a kind of self-aware irony, where the characters' lack of knowledge about zombies or alien invasions contrasts with the audience's understanding, who are familiar with the genre conventions and tropes from other films.

By referencing 'Independence Day', Cline is specifically addressing the alien invasion genre, noting that in a movie about an alien attack, it’s often as though the characters have never seen a film where humanity fights back against extraterrestrial invaders. This adds a layer of realism or novelty to the scenario, as the characters react to the events with fresh, uninformed perspectives, even though the audience recognizes the familiar tropes from other movies.

Ultimately, Cline’s quote reflects on the meta-nature of genre films and the way they play with audience expectations. It also highlights how characters in these films often lack the awareness of the genre’s conventions, even as those conventions shape how we, as viewers, interpret the unfolding events. It’s a commentary on how genre films work within their own fictional universe, often ignoring the influence of similar stories in the real world.