Juste Leblanc comes from Le Dîner de Cons, the 1998 French comedy by Francis Veber, adapted from his stage play. Jacques Villeret plays François Pignon, a guest invited to a dinner where rich hosts mock supposedly foolish guests. In one celebrated exchange, Pignon tries to explain that Leblanc's first name really is Juste, creating a misunderstanding that French audiences have quoted for decades. The scene later circulated widely in clips, reaction videos and French soundboards, where the name alone signals polite confusion and wordplay.