I thought this would be more Four Weddings and a Funeral, but all the lives/deaths in the title belong to Marcello Mastroianni, who lives at least three different lives in this almost-anthology movie.
Birds and snake:
Firstly, Marcello had walked out on his wife, rented an apartment down the street, and fallen asleep for 20 years, hypnotized by tiny Parisian fairies. When he escapes, he talks his wife’s current guy (Féodor Atkine of a couple Rohmers) into listening to his story, then coming to the apartment and taking his place (less “talks” and more “kidnaps and murders” at that point) while Marcello returns to wife Marisa Peredes (an Almodóvar regular).
Atkine, swimming in chicks
Then Marcello is a bachelor professor with an invalid mum until he gets the sudden urge to leave home and becomes a very successful street beggar and befriends CEO/prostitute Alla Galiena (The Tulse Luper Suitcases), living a double life with her dangerous husband.
Galiena and perverse husband:
Polyamorous couple Martin (Ruiz fave Melvil Poupaud) and Cecile (Marcello’s daughter Chiara Mastroianni) have a mysterious benefactor in Marcello, who leaves them a mansion then performs as their mute butler, and this turns out to be a scheme to steal their newborn and deliver it to Wife #1 Marisa Peredes. Marcello is introduced as a fourth character, a businessman whose young wife is cheating on him, but we’ve already seen characters from the other stories interacting, and now it turns out there’s only one Marcello, and he starts rapidly flipping between personas, then all Marcellos share one death after a fateful meeting at the cafe between the women from each chapter.
A Poupaud and two Mastroiannis:
Marcello is excellent in this, and would die a couple months after it came out. It played a stacked Cannes with Crash, Fargo and Breaking the Waves.