My favourite film director, Billy Wilder, talking to The Paris Review about the origins of one of his Oscar winners:

INTERVIEWER

You’ve indicated where Lubitsch got his ideas. Where do you get yours?

WILDER

I don’t know. I just get them. Some of them in the toilet, I’m afraid. I have a black book here with all sorts of entries. A little bit of dialogue I’ve overheard. An idea for a character. A bit of background. Some boy-meets-girl scenarios.

While I was working with Mr. Lemmon for the first time on Some Like It Hot, I thought to myself, This guy’s got a little bit of genius. I would love to make another picture with him, but I don’t have a story. So I looked in my little black book and I came across a note about David Lean’s movie Brief Encounter, that story about a married woman who lives in the country, comes to London, and meets a man. They have an affair in his friend’s apartment. What I had written was, What about the friend who has to crawl back into that warm bed?

I had made that note ten years earlier, I couldn’t touch it because of censorship, but suddenly there it was—The Apartment—all suggested by this note and by the qualities of an actor with whom I wanted to make my next picture. It was ideal for Lemmon, the combination of sweet and sour. I liked it when someone called that picture a dirty fairy tale.