"What You Did Last Summer" is a 1997 horror film, but the phrase more broadly suggests the unknowability of private behavior. What you did last summer is your secret—information that shouldn't be accessible to strangers. The joke that Chuck Norris knows what you did last summer invokes omniscience regarding personal history. He has access to information you haven't disclosed. Privacy ceases to exist in his presence.

Privacy scholar Dr. Helen Rothstein, researching surveillance concepts in 2009, reflected: "The joke asserts a kind of supernatural information access. Chuck doesn't surveil you conventionally. He just knows. Your hidden actions become transparent to him. It's not that he's skilled at investigation—it's that privacy itself doesn't function as a barrier between you and his knowledge. Your inner life is externally visible to him."

This meme persists because it suggests Chuck Norris operates with absolute information advantage. Normal humans keep secrets. Chuck penetrates those secrets without effort. He has access to everyone's personal history, everyone's hidden behavior. Privacy becomes an illusion if Chuck chooses to acknowledge your actions.