It’s established early on that "Antoine Doinel" (Jean-Pierre Léaud) isn't exactly dependable, and the opening moments really show this. The divorce from "Christine" (Claude Jade) is fresh when he abandons "Sabine" (Dorothée) to be with their son "Alphonse." This pretty much highlights the issue for "Sabine," who just wants a bit more dedication from her unreliable boyfriend. He's still trying to manage everything, and it’s not working out well for anyone, which is shown in this amusingly assembled story that uses flashbacks and current events, getting even trickier when he bumps into his old crush "Colette" (Marie-France Pisier) – and without a train ticket, no less! For "Antoine," it's a whirlwind of feelings pulling him every direction, often leaving him struggling. But who could possibly make him happy? Could he actually bring joy to someone if he ever puts aside his own desires? Is that even possible for him? There’s good rapport between Léaud and both Pisier and Dorothée, and the comedy sometimes comes close to being broad, but it avoids going too far as his character elicits laughter mixed with sympathy and embarrassment when we watch his life fall apart. Truffaut keeps a brisk pace throughout, and there's some clever observation in a script that rather touchingly portrays a man I think it would be best not to know – particularly if you’re a woman.

Source on TMDB