The line comes from Forrest Gump (1994), where Forrest recalls his mother, Mrs Gump, telling him that stupid is as stupid does, meaning people are judged by their actions rather than their intelligence. Spoken by Tom Hanks, the quote became one of the film's most remembered lines and has lived on in clips, soundboards and social media edits long after the film's release. Its popularity endures because it works as a gentle, quotable put-down: familiar enough to be recognised instantly, yet soft enough to use playfully against friends, celebrities and fictional characters alike.