The line is closely associated with The Godfather Part II, released in 1974, where Michael Corleone repeats advice about watching enemies even more carefully than friends. The phrase has since entered everyday speech as a shorthand for cautious strategy and mistrust, appearing in business advice, political commentary and countless memes. Short audio clips of the line circulate on soundboards and in video edits because the wording is instantly recognisable, even to people who have not seen the film, and it instantly frames a situation as calculated rather than accidental.