The English title of the movie “400 Blows” is a gross misinterpretation of the original title. The Finnish and Swedish translations of the title, roughly translatable to “400 practical jokes” are closer to the original meaning, albeit not perfect. The original title stems from the French expression “Faire les quatre cents coups”, meaning “to live a wild life”, as the main character does. Literal translation of the expression would be “to do the 400 dirty tricks”.

All the young actors who unsuccessfully auditioned for the role of Antoine were used in the classroom scenes.

So pleased with Jean-Pierre Léaud and his screen test (an informal conversation with the film’s director being off-camera), François Truffaut doctored it into the finished film by using fade-outs and substituting his voice with an off-camera female psychiatrist’s voice.

When Antoine and Rene are suspended from school, they go gallivanting around the town. At one point they pass a wall of posters and flyers, and they pull off a picture of a woman. The woman is Harriet Andersson in a shot from Ingmar Bergman’s Sommaren med Monika, about two young lovers who ran away from home to “live their own life.”