Some years ago I read Philippe Besson's book, and thought it a bit on the sentimental side. But this movie-adaptation is excellent, it doesn't thrive on emotional effects, but tells the story in a very sensitive, almost restrained way, making it all the more poignant. It's intelligently done, the present alternating with flashbacks, while we see how the harsh truth very gradually, with every new scene, dawns on main character Stephane.
The nostalgic atmosphere is wonderful, the 80's setting in the flash backs are convincingly done, and both young actors Jérémy Gillet and Julien de Saint Jean do a fine job. But the stars of this movie are Guillaume de Tonquédec and Victor Belmondo: De Tonquédec as the middle-aged writer Stephane, who comes back to his hometown to evoke the memories of his first great love, that back then so mysteriously dead-ended; and Belmondo as Lucas, who lives with a distorted memory of his father and now finally gets to see him in a very different light. Both actors are totally convincing, and the way they play the pivotal scene, in which Stephane holds a long impromptu speech for a posh gathering, but in fact for the sake of Lucas and the memory of his dead father, is deeply moving.
The point that is made here is comparable with that in Brokeback Mountain: how the shame and fear of showing your true (gay) self to the world can poison and waste a whole life. It's so true, and unfortunately still as relevant as ever.