It's 19:45 p.m. The bell rang for another hour and the world of classical Greece beckoned to the pensioner who neatly placed his pencil case and textbooks on the small wooden bench. Dressed in a dark suit and polished loafers, Vassilis Panagiotaropoulos is by far the oldest student attending the Second Evening School in central Athens. At least half of his classmates are the age of his grandchildren, he writes "The Guardian".

Almost 70 years have passed since Vasili was last at school.

"I quit at 12 to help my father in the fields," he says, recalling his childhood in a village in the Peloponnese. "But in my mind and soul I always wanted to come back." It's a desire that never went away."

When he turned 80, the former tavern owner told his wife, Maria, a retired seamstress, that he would finally get that wish. After nearly five decades of working as a chef and running his own business ("hard work, hard life") in the Greek capital, he entered the iron gates of the Second Evening School last year.

Today he is enrolled in a class that a 15-year-old would normally be enrolled in – a thought that makes his face smile before he smiles. "Ah, to be 15 again," he says. "I always had this dream, to be filled with knowledge, but I never thought the day would come when I would actually live it."

Panagiotaropoulos' life-changing decision went viral when he led the school's flag-bearer in a school parade to mark last month's anniversary of Oxy Day - commemorating Greece's decision to defy Italian forces and enter World War II on the side of the allies. He was filmed proudly marching in front of the Greek Parliament.

"He was given the honor of carrying the flag because he was the best student in the class," says Evangeliia Pateraki, the school's principal. "He is extremely hardworking and offers a lot to other students." It's very touching to see people who didn't have the same opportunity, who had to work, going back to school," she adds.

In Greece, whose population is predicted to decrease drastically over the next 25 years quarter of a century, the pensioner's decision is particularly interesting. By 2050, around 35 percent of Greece's population will be over the age of 65, according to Eurostat.

"In societies like ours where life expectancy is increasing, it sends a message to people of a similar age that it's never too late in life." But it also helps those at a younger age to cope with ageing," says Dr. Pavlos Baltas, a demographer at the National Center for Social Research.