Apple + Prince William
Prince William is shedding new light on the difficulties he faced as an air ambulance pilot.
The Duke of Cambridge, who previously worked as an air ambulance helicopter pilot after serving as an RAF Search and Rescue pilot, recalls his own mental health struggles in a special episode of Apple Fitness+'s Time to Walk series, which premieres on Dec. 6.
"The moment I started the helicopter training, I realized that it was better than anything. It was one of those things that I just instantly took to and thought, 'This is really cool.' I really enjoy it," says William, who began working with the East Anglian Air Ambulance in 2015 and left the role in 2017 to focus on his royal duties.
For more on Prince William's episode of Time to Walk and other top stories, listen below to our daily podcast on PEOPLE Every Day.
But on the job, the royal faced "difficult situations."
"Seeing patients and families ripped apart on almost a daily basis, that routine, you just get into a habit of head down and get on with it," he says.
One call particularly affected the royal.
"Immediately it became clear that this young person was in serious difficulty, sadly been hit by a car," he says. "And of course there are some things in life you don't really want to see."
"And all we cared about at the time was fixing this boy. And the parents are very hysterical, as you can imagine, screaming, wailing, not knowing what to do, you know, and in, in real agony themselves. And that lives with you," he continues.
William says his team stabilized the young boy, but when he returned home, he couldn't shake the experience.
"I went home that night pretty upset but not noticeably," he shares. "I wasn't in tears, but inside, I felt something had changed. I felt a sort of, a real tension inside of me."
The royal says he continued his work without processing his feelings.
Apple + Prince William
"It really hit me weeks later," he continues. It was like someone had put a key in a lock and opened it without me giving permission to do that. I felt like the whole world was dying. It's an extraordinary feeling. You just feel everyone's in pain, everyone's suffering. And that's not me. I've never felt that before.
"My personal life and everything was absolutely fine. I was happy at home and happy at work, but I kept looking at myself, going, 'Why am I feeling like this? Why do I feel so sad?' And I started to realize that, actually, you're taking home people's trauma, people's sadness, and it's affecting you.
"I was lucky enough that I had someone to talk to at work in the Air Ambulance because mental health where I was working was very important.
"Talking about those jobs definitely helped, sharing them with the team, and ultimately, in one case, meeting the family and the, the patient involved who made a recovery, albeit not a full recovery, but made a recovery."
William's work as an air ambulance helicopter pilot helped inspire him to spread awareness about the importance of supporting mental health and wellbeing.
"We know mental health has been a taboo and a stigma for a long time all around the world. And it still is," he says. "I'd like to think, in the U.K. here and the U.S., it's much more talked about, and it's opening up. But there's still a deep-rooted fear of understanding it.
"And we all need to go through a process of understanding why rather than just give in to those feelings and say, 'Listen, it's me. I'm the problem.' It's not. It really isn't you.
"And you're not alone, and it's okay. It's about what you do next. It's about having that boldness and that openness and that strength to go, 'It's going to be a long journey. It's not going to be easy, but I'm going to get there.' "
Apple + Prince William outside St. Mary Magdalene Church
William approached Apple to take part in Time to Walk as he was impressed with the series and how it coincided with his efforts to promote better mental health.
During the episode, the royal talks about the importance of keeping mentally fit, reflects on a light-hearted moment when he was drawn out of his comfort zone, the value of listening as a way to empower others and an experience that led him to prioritize mental health. Prince William also chooses three of his favorite songs and explains why they are important to him.
Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more!
Recognizing the significant impact that walking has on mental health and that the holidays can be challenging for many, William has chosen three charities to receive a five-figure donation from Apple: Shout in the UK, Crisis Text Line in the USA and Lifeline in Australia. Crisis Text Line and Shout provide free, 24/7 confidential support for people in crisis via text, and Lifeline provides free, 24-hour confidential crisis support and suicide prevention services.
Apple will stream three special audio airings of the Time to Walk episode for free on Apple Music 1, the flagship global radio station on Apple Music, on Dec. 6.