Tralala, in his forties, singer in the streets of Paris, one evening crosses paths with a young woman who sends him a single message before disappearing: "Above all, don't be yourself". Did Tralala dream? He leaves the capital and ends up finding in Lourdes the one he is already in love with. She no longer remembers him. But a moving sexagenarian believes to recognize in Tralala her own son, Pat, disappeared twenty years before in the United States. Tralala decides to take on the "role". He will discover a new family and find the genius he never had.