An absurd law prevents John, an unrecognized child at birth, from knowing the identity of his biological parents before his 100th birthday. To succeed in attracting public opinion, his only hope is to obtain the complicity of Gustavo, the only unrecognized-at-birth centenarian alive. The only one who would have the right to avail himself of this legislation but seems to have no interest in doing so. The Most Beautiful Century of My Life tells of the meeting between a centenarian projected into the future and a young man anchored in the past and of their unexpected friendship.
In a large villa on Lake Como, everything is ready to celebrate Elio and Caterina's wedding. It will be the most beautiful day of their lives and also of their parents' lives, especially their respective fathers, Giacomo and Giovanni. Too bad that together with Margherita, Giovanni's ex-wife and mother of the bride, Aldo, her new partner, also arrives at the wedding. Friendly, outgoing and above all a total troublemaker. Giacomo and Giovanni try to contain him in every way, but under Aldo's blows, cracks open up from which a hidden malaise emerges, destined to call into question the friendship between Giovanni and Giacomo, their marriages and more. And that will force everyone to deal with their own doubts and with the courage it takes to allow themselves happiness.