There has never been a movie where a middle-age couple go on the run, pursued by teenage cops. This is the sort of thing that's so obvious it never occurs to anybody. All lovers on the run are young. All cops are older. That's because road movies are to late adolescence what monster movies are to kids: a way of exorcising unease. Little kids identify with monsters because, like Godzilla, they feel uncoordinated and misunderstood. Moviegoers in their teens and 20s identify with road movies because, like their fugitive heroes, they feel a deep need to leave home, to flee adult regimentat...