What an excellent coincidence that Monday's great film, Brief Encounter, influenced today's, The Apartment (1960). Here's how: 'Seeing David Lean’s Brief Encounter, about an adulterous affair conducted in the apartment of a third party, Billy Wilder scribbled this idea in his notebook: “What about the poor schnook who has to crawl into the still-warm bed of the lovers?” Years would pass before Wilder felt he could slip this concept past film censors.' (more about Wilder here).