He was once known as the "lad" of the Royal Family, most at home surrounded by friends from the army and aristocracy, and possibly down the pub.
The Duke of Sussex this week proved he has made the full spiritual transition to his new home of California, as he let slip his newfound bond with the A-list's favourite self-help guru.
The Duke, who has recently been sporting a tan and casual clothing to suit his life in the Santa Barbara sun, disclosed he now "absolutely adores" none other than Brené Brown, the TED Talk phenomenon who has become a friend.
Brown, whose many notable admirers include Oprah Winfrey, Melinda Gates and Gwyneth Paltrow, is a writer, podcaster and prolific sharer of inspirational quotes about vulnerability, courage and overcoming shame.
The Duchess of Sussex is an admirer; she included an article from Brown entitled "Speak Your Truth. Follow Your Wild Heart" in her guest-edited issue of British Vogue.
Prince Harry, who in 2019 spoke of his daily meditation habit, this week revealed he too has embraced her teachings, in an excitable name-drop during a video call.
As the Sussexes spoke to young leaders during an online event with the Queen's Commonwealth Trust, the Duke's face lit up with recognition as one participant, the founder of Australian charity The Man Cave, quoted both Brown and Tristan Harris, who runs the Centre for Humane Technology.
Speaking of the importance of young men embracing their vulnerable side as well as their traditional masculinity, Hunter Johnson quoted Brown to say: "Vulnerability brings connection, and connection is why we are here."
Smiling and turning to look at the Duchess, the Duke said: "I love the fact you're quoting Brené Brown and also quoting Tristan Harris because they are two people we absolutely adore as well, and we know." The Duchess added: "We love them!"
The couple are understood to have been in contact with Harris over their mission to reshape social media into a more "positive" community.
Once called "the closest Silicon Valley has to a conscience", he has previously spoken of the dominance of technology as the most "urgent problem" facing the modern world, saying: "Never before has a handful of people working at a handful of tech companies been able to steer the thoughts and feelings of a billion people."
Archewell, the Sussexes' future non-profit organisation, was this week described for the first time as being intended to "build compassionate communities online and off to serve our collective wellbeing".
Brown wrote for Meghan's edition of Vogue on a similar theme: the cruelty of online comments and the impossibility of being immune to their effects.
"The only foolproof strategy I've come up with so far is this: owning our story, owning what we believe, and loving ourselves is the bravest thing we'll ever do," she wrote. "Do the world a favour: speak your truth. Follow your wild heart."
Prince Harry is known to have previously been upset by reading comments on online stories about himself and his wife.
The friendship provides a new insight into the Sussexes' lives in California, where they are surrounded by a new crop of rich and famous friends far removed from their lives in Britain. Their Santa Barbara neighbours reportedly include Oprah Winfrey and Ellen Degeneres.
Brown has been described as the "world's biggest self-help guru", with a celebrity following including Reese Witherspoon, Jennifer Aniston and Paltrow, who called her "one of the most influential people in our culture right now".
A research professor at the University of Houston, her TED Talk on "the power of vulnerability" has been viewed 50 million times, and five number one New York Times bestsellers include The Gifts of Imperfection, Daring Greatly, Rising Strong, Braving the Wilderness, and Dare to Lead.
A member of the Episcopal Church, her inspirational quotes are a favourite of Instagrammers.
Offerings that may chime with the Sussexes recently include "daring leaders are never silent about hard things", "let go of who you think you're supposed to be; embrace who you are", and "you can't take criticism and feedback from people who are not being brave with their lives. It just will crush you".