In 1955, Apollonio graduated from the Slovenian High School in Koper and passed the entrance exam to the Academy of Fine Arts in Ljubljana. He studied painting under Slavko Pengov, Riko Debenjak, Marij Pregelj, and Maksim Sedej. He graduated in 1960 under Gabrijel Stupica and continued with postgraduate studies in painting under him, which he completed in 1964. Between 1964 and 1968, he taught art at a teacher training college and high school in Koper. He travelled through Italy, Spain, France, and the Netherlands. From 1968 to 1973, he worked as a freelance artist in Koper. From 1973 to 1990, he was employed at the Academy of Fine Arts, first as an assistant professor, then as an associate, and later as a full professor. Between 1981 and 1987, he was the head of the graphics department and from 1984 to 1987, he served as vice-dean of the Academy. He retired on disability in 1990 and from 1989 onward lived and worked in Portorož.

In his biography, he wrote about himself: “I believe that the time and place of my birth (May 15, 1935, in Bertoki near Koper) are not mere coincidences but significant factors that have profoundly impacted my life since childhood. I was born under the sign of Taurus, a mythical and earthly creature full of life drive, tragedy, kindness, naivety, imbued with relentless perseverance, and an insatiable longing for beauty, goodness, and pleasure. If this has marked my character traits, then the second fact, the place of my birth, marked my life path. Born in a place where history bestowed neither grace nor glory, just the harsh reality of everyday life between sea and shore, in a small village of humble, almost poor farmers who grew vines and olives. From my ancestral home, it’s only a stone’s throw to the sea. In summer, as children, we splashed in the shallow waters, chased crabs, caught fish, eels, and gathered shellfish. A dusty road from the village leads to the parish church and cemetery, where my prematurely deceased father, two brothers, and my mother Antonija—who survived all wars and the many states that passed through this region in the last century and died at 94—are buried. To her, I will always be grateful that all my journeys led me back home. Two of my sisters who went out into the world, like me, continually return home.”

Zvest Apollonio died on March 25, 2009, in Bertoki.