It's a Mad, Mad Vengos (1967)

Engaged to Anthoula, the love of his life and the little sister of seven brothers and owners of the tavern where he is employed as a waiter, the indefatigable and hard-working Thanassis simply can't wait for his marriage. Unfortunately, by an unlucky twist of fate, the faithful groom will suffer a clumsy, yet stunning blow to the head only a few hours before the nuptial ceremony, causing a profound, disastrous, and seemingly irreparable amnesia. Now, having lost any recollection--not only of the imminent joyous event but also of his very personality--the runaway Thanassis will wander around a faceless Athens taking odd jobs, while at the same time, an inconsolable Anthoula faces the crisis of a lifetime. Has modern medicine anything to offer, or is a more drastic measure needed for Thanassis' curious case?