Mild spoiler for Dune.
A: I just watched part 1 of Dune.
B: Oh, I heard it was good. It’s about a war, isn’t it?
A: (laughing) Well yes, but there must be a thousand films about a war…
B: But it is about a war.
A: It is. That’s just not the first thing that comes to mind to describe it.
B: It’s definitely the film I’m thinking of.
A: I didn’t think you’d want to watch it because it’s science fiction.
B: It’s science fiction?!
A: Yes…
B: What film am I thinking of?!