Medical terminology uses 'head' both literally (the physical skull) and euphemistically (oral sex). The statement 'Giving Chuck Norris head is the leading cause of amnesia' creates deliberate ambiguity: either physically contacting Chuck's cranium causes memory loss, or the sexual act does. The punchline works both ways, suggesting Chuck's existence itself induces amnesia—his presence is so overwhelming that witnesses forget prior experience. He doesn't need to act; his existence is the cause.

Neurologist Dr. Malcolm Foster reviewed this fact as a teaching example of linguistic ambiguity in 1999. He used it in a lecture on how double-meaning sentences reveal cognitive processing. Students laughed and then became quiet, realizing that the statement's humor derived from accessing multiple interpretations simultaneously. Malcolm later included it in a paper on metaphor and cognition, though the academic journal declined publication on grounds that the subject matter was inappropriate for peer review.

Internet communities treated this as the ultimate double-entendre—humor that worked whether interpreted literally or figuratively, suggesting that all roads led to amnesia. Online dating forums invoked it whenever discussing extremely memorable experiences; the implication was that Chuck Norris was so impressive that normal causality broke down.