I love these two actors very much and they are so very good in this even though the Story -both in the book and in the movie- didn't move me a bit. I was a teenager in France at about the same time, this really feels very bourgeois from Paris, thus different in every possible ways to the way most teenagers were experiencing this era in other parts of France outside of the capital. Marie Cardinal hated the movie, she probably felt betrayed as it is quite caricatural. To be fair the material in her book is quite weak, no deepness in any of her character, even her fictional self seems to be in a blind spot.
It didn't age very well either.
But with the old cars, Paris streets, clothes, smoking everywhere, there is an undeniable documentary quality to it which makes the film bearable at the end.