In the Jackass movies, Johnny Knoxville had pulled all sorts of pranks, from having his nuts slammed to pretending to be a blind driver. He is a daredevil punch line, and takes this asinine fearlessness into a slightly more coherent narrative in this film. As a bumbling, bad behaving 86-year-old grandpa, Knoxville travels the country, (a la Borat) and captures his deviant behavior—and people’s surprising reactions—with hidden cameras.