Jack O’Connell may be on the precipice of glory, but the 24-year-old is mindful of the journey ahead. While the British actor has racked up credits and acclaim across the pond (This Is EnglandSkinsHarry Brown) and drew raves for his turn as a volatile young inmate in this year’s award-winning drama Starred Up, this Christmas he tackles his most challenging role yet: Playing American hero Louis Zamperini in Universal’s Unbroken.

Angelina Jolie directs the biopic about the Olympic track star, who enlisted in the Air Force when he was O’Connell’s age only to crash land in the Pacific, surviving 47 days adrift in a raft. “Rescued” by the Japanese, Zamperini endured years in brutal prisoner of war camps until World War II drew to a close. The role demanded extreme emotional and physical transformation from O’Connell, who credits the example set by Zamperini, who died in July, for getting him through the demanding shoot. “I knew I was going to stay alive because I had professionals working with me,” he says. “Louis didn’t know that.”

Louis Zamperini’s journey took him so many places emotionally and physically; it was a lot for a human being to endure. What did he impress upon you most, and what do you hope people take away from his story?

For me, Louis’s main ethos is selflessness. Whether his ability to be selfless was beaten into him against his will or was there prior to him joining the Air Force in his experience as a youngster, he was ego-free. I do believe that kept him alive. The main thing I’ve taken away in a comparison between my generation and his is that nowadays there’s a lot more emphasis on the individual. People say “I” a lot, whereas before, that was considered rude. His generation inspires me to no end. I feel a bit more advantaged in this day and age because of that mind-set.

That selflessness also came from being a symbol of inspiration from those around them—not only in the prison camps but as an Olympic athlete.

Yes, but he never considered himself a hero. Any time I spoke with him, he had a tendency to avoid ever dwelling on how things made him feel. He was quite happy stating the facts of his experience, even making jokes about the facts. It was quite difficult getting him to open up. There were people around him that knew him better than I did and could interrogate him more, but it was to no avail. He’d just make the joke.

How important was it to be able to interact with him before his death?

I think it was crucial—and it would have been neglectful of me to go anywhere near Australia without spending a little bit of time with him first. I had two meetings with him before the shoot and I spent a lot of time preparing before that. It was invaluable; I picked up a lot of facial expressions and his reactions, but I also got to see what made him tick. I had an uncensored version of him to refer to.

By the time you met him, he was years removed from the man who endured war and imprisonment. What was the most difficult element of the young Louis for you to capture?

There was literally no audio of him from that time during the ages I portrayed him. I was able to hone in on his style of running but there wasn’t anything I could use in terms of finding his voice. That’s when Angie delivered a brilliant note right on time, just prior to the shoot: She said she wanted to hear my voice within the dialect. I think that really rescued my accent. Prior to that I was struggling trying to chase something I wasn’t going to achieve.

You also transformed physically to play Louis as a healthy Olympian runner and, later, a severely malnourished prisoner. Why was that important to do?

If I didn’t achieve that, I didn’t deserve the role. It was always a requirement—and there are a lot of actors out there who have achieved that, and to a larger extent than what was required by me. I was also constantly dwarfed by the fact that I knew whatever I was experiencing wasn’t the worst any actor has experienced on set, nor anywhere near what Louis must have felt. I knew I was going to stay alive because I had professionals working with me. Louis didn’t know that. It put a lot into perspective for me, about my priorities. It was quite replenishing to go through. I advise anyone else to do it.

Do you view life differently now?

Angelina had a great quote. She said if she ever wakes up in the morning and starts thinking about herself and her priorities, it pisses her off. I didn’t realize just how ugly selfishness actually is, and there’s a lot of it in society today. I don’t think I’m going to change anything there. All I can do is hope my example might inspire others, and I certainly learnt a lot of it from Louis. I think life is probably pointless if there isn’t an element of devotion somewhere. I hope to achieve that now going forward.

You’re getting major awards attention in what marks your biggest role to date, with Hollywood knocking on the door. How do you retain any perspective amidst the glitz?

I know what’s important to me. I know that all of these things can be preserved, however successful I am as an actor. I’ve got good people around me and that’s what I feel devoted to. I’ll just stick to what I know and keep moving forward. Best advice I was ever given was to keep focusing on what’s next. It’s quite difficult when you find yourself on a press tour! But it’s now a case of making the right decisions and raising the barrier. Unbroken is easily my best piece of work yet, but I will be reluctant to concede that it’ll be my best piece of work, ever.