As Eldritch points out, the word Plot usually refers to the coherent narrative that a typical screenplay needs, but it's also characteristically used by conspiracy theorists and potheads to refer to an illusory Pattern projected on the world's Nebulosity.
It's a basic rule of screenplays that every line of dialogue should carry the Plot forward. In drama, acting mostly means talking. But a film narrative is made up of words and actions. In a central paragraph, MacIntyre writes:
So the film has Plot itself as an ironic theme. It's hard to remember the actual plot of the film because it's so convoluted, digressive, and random. Like the Dude says: