Bienvenue chez les Ch'tis

Philippe Abrams is the manager of the postal service (La Poste) in Salon-de-Provence, Bouches-du-RhÃ´ne, in southern France. He is married to Julie, whose depressive character makes his life miserable. Philippe does everything to get a job at an office on the Mediterranean seaside to make her happy. As this favourable position will be granted to somebody who is disabled, Abrams decides to pretend that he is. However, the management finds out. As punishment, he is banished for two years to Bergues, a town near Dunkirk in northern France. Northern France â and the Nord-Pas-de-Calais region in particular â is considered "the sticks" â a cold and rainy place inhabited by unsophisticated ch'tis who speak a strange language (called "ch'ti" in local parlance, and "cheutimi" in the South). He has to spend his first night at the home of Antoine, a co-worker of his. Philippe initially dislikes Antoine for his rude behaviour and because he thinks Antoine is gay (he found photographs of Antoine dressed as a woman, but they were taken during a carnival party). However, later in the film, Antoine and Philippe become best friends.
To Philippe's surprise, Bergues proves to be a charming place teeming with warm, friendly people and co-workers. Soon, he is completely won over, eating smelly Maroilles cheese; talking to virtually every local (by delivering their mail, and accepting the recipient's invitation for a drink); playing at the beach; playing the bells at the bell tower together, drinking beer like a local, going to an RC Lens football match and so forth. He tries to describe the happy turn of events to his wife who has remained in the South with their young son, but she does not believe him. This inspires Philippe to tell her what she wants to believe: that his life is wretched there.
Everything goes fine until Julie decides to join him in the North to relieve his gloom. Philippe is forced to confess to his new friends and colleagues that he has described them as barbarians to his wife. First, they are angry, but they then decide to help him by behaving as such to cover for his lies and to scare Julie so she will depart quickly. Also they let her stay in the old mining place of Bergues, pretending it is the main town. Julie has a very bad weekend, but decides she will move to Bergues to stay with Phillipe, to be supportive.
Just when she's ready to go back south, she discovers that she has been tricked when a local biker tells Julie that the actual town of Bergues is several kilometers away. When Philippe finds Julie at his real Bergues home, he tells her the truth about the happiness and friendship that the town has brought him. Julie is disappointed at first, but after realising her husband is happy, she decides to move north to be with him.
Meanwhile, Antoine and Annabelle had been dating for over a year, but had broken up due to Antoine's passiveness towards his mother. Despite their split, Antoine still has feelings for Annabelle, who now has a new boyfriend. Upon learning this, Antoine cheers himself up by drinking alcohol during his work hours and behaves in an erratic manner. When Phillipe urges Antoine to take courage and be assertive, Antoine finally confesses to his mother that he loves Annabelle and is planning to move to a new place with her. Unexpectedly, his mother is happy about it â she has waited all these years for Antoine to stand up for himself. As a result, Antoine proposes to Annabelle by the bell tower when it is playing a Stevie Wonder song. Annabelle accepts, and they get married.
Three years later, Phillipe receives a transfer to move south. Accepting the offer, Phillipe and his family move south. Just as he is about to say goodbye, he is reduced to tears, proving Antoine's theory on the Ch'tis proverb ("A visitor brays [cries] twice up north: once on his arrival and once at his departure.")

Question: what is proverb mentioned in movie?
Answer: A visitor brays twice up north: once on his arrival and once at his departure; A visitor brays twice up north: once on his arrival and once at his departure