Listening to a musical program on the radio, each of the listeners remembers these "little nothings" (the title is borrowed from Mozart's ballet-pantomime, Les Petits Riens) which have often changed their lives. The film is presented as a sketch film where everyone tells their story by proving that a tiny detail can change an entire destiny. The painter: Painter refused at the salon, Drial is one day knocked down by a car, he is rescued and transported to the hospital but his painting is lost, it falls into the hands of a concierge who resells it to a discerning collector. Leaving the hospital Drial realizes that he has become famous. Astier: Astier is a receptionist in a hotel, he finds Lefebvre an old childhood friend who encourages him to stake all his savings in a stock market transaction. Astier presuming of his future fortune leaves his job and learns that he is ruined when he returns to see the stockbroker. He then becomes a hearse driver, it is there that he meets Lefebvre again who buries his mother-in-law. The latter informs him that his shares have gone up and that he is now a millionaire. Mesnard: Mesnard is a pawn in a provincial high school and writes plays under a pseudonym. His childhood friend tells him that a theater is ready to play one of these plays. Refusing to go to the rehearsal, he waits for a phone call from his friend who informs him that the first act is catastrophic. Suddenly, as he is dressed, Mesnard takes the opportunity to replace his father as servant in a reception on the floor above. But it turns out that the rest of the play obtains a colossal success, Mesnard then plants there the bourgeois whom he served. Les Brignoles : Monsieur Brignoles sets up a scheme to deceive his wife with Louise, her best friend. While he is supposed to be in Brussels, Madame Brignoles learns by chance that he has stayed in Paris. As for Louise, who was to organize a hunting party in the countryside, she also remained in Paris. Madame Brignoles goes to Louise's, spends time with her while the husband remains hidden in the apartment. Not fooled, leaving the cinema, Madame Brignoles told Louise to ask her husband to hurry home. But on returning home she receives a telegram from Brussels signed by her husband. La Clermont: It is whispered that the king of Sinistrie died in the arms of La Clermont. All of Paris is aware except La Clermont herself who, tonight, is playing Molière. The public and the press praise his great courage. It is only at the end of the performance that she learns of the king's death. She does not deny anything, but soon receives a telegram from her lover who, jealous, decides to break off abruptly. Charpillon: Charpillon marries Lucie, his young secretary. During the private wedding dinner, she shows him a medallion containing the portraits of her parents. The medallion accidentally falls freeing another photo, that of Lucie's lover. Good prince, Charpillon does not retain Lucie and offers her the two train tickets for the honeymoon.