More than 80 years after World War II ended, 102-year-old veteran Brian Barry has shared a powerful message about the horrors of war and the importance of remembering those who served.

Barry, who enlisted at age 18 and served in New Guinea for two-and-a-half years, spoke candidly about what Anzac Day means to him and his concerns about the modern world.

“It’s a day of remembrance, truly,” Barry told Natarsha Belling during an emotional interview on 7NEWS.

“You lose good friends, people you’ve only just met actually, and they come and disappear in your life.

“But it’s the mateship that you find in those positions.”

The centenarian recalled how unprepared he was for what lay ahead when he left Australia as a teenager.

“I’d never been outside Australia. The furthest I went was in a ferry to Manly, that was my trip. And then I enlist to go overseas,” he said.

Reflecting on the young lives lost in battle, Barry’s voice carried the weight of decades of memory.

“You think of all those young lives that go in to battle and never come out, you know,” he said.

“They go in, young boys, and they come home in a coffin. It’s a terrible thing.”

He expressed frustration that, despite promises World War II would be the last war, conflicts have continued.

“From there on, there’s been a war every year and it doesn’t seem to be getting any better,” he said.

Barry was particularly troubled by a recent survey which found many people would not volunteer if war broke out involving Australia.

He also condemned anyone who vandalises war memorials.

“They’d tip paint all over memorials — I mean, they ought to catch him and then tip paint over him and leave him sitting in it for a couple of days,” he said.

Despite the hardships, Barry recalled moments of humour during his service, including a flood at the base that destroyed a piano gifted by the Salvation Army.

“Chaps walking around saying, ‘You didn’t see a pair of boots with false teeth in it?’ Funny things like that,” he said.

When asked about his secret to longevity, Barry’s answer was simple: “A lovely family, a terrific family.”

He spoke fondly of his late wife, Rose, whom he met when they were both 15.

“Your kids make your life, especially your grandchildren,” he said.

“I mean, you look at your grandchildren, you think, aren’t they lucky to have them? Because not everyone can have kids.”

Barry said he never imagined reaching the age of 102, and expressed gratitude for the opportunity to share his story.

“I’m very grateful for being here and having your kind invitation. It’s something I’ll cherish for a long, long time,” he said.