Excerpt from Conversations with Wilder
[Lubitsch] realized that if you say two and two, the audience does not have to be told it’s four. The audience will find it themselves; let the audience find the joke. There was always an innuendo, in setting up situations, and you were rewarded by the laugh of the people who added it up.
“Lorne Michaels should take note.”
Amen, sister.