Dark Knight Co-Writer Reveals Truth Behind Line That Plagues Christopher Nolan

“Why so serious?” The late Heath Ledger spoke those iconic words as the Joker more than once during the course of filmmaker Christopher Nolan’s critically acclaimed Batman movie, The Dark Knight. However, even though that line uttered by the Clown Prince of Crime has so much impact in the film, it’s another line of dialogue that Nolan is actually “plagued by." While attending the SXSW film festival to promote his upcoming Prime Video series, Fallout, Nolan's brother, Jonathan, elaborated on the now famous line uttered by actor Aaron Eckhart’s Harvey Dent in The Dark Knight. Jonathan, who served as a co-writer on the film, told The Hollywood Reporter: