Prince Harry has long been an outspoken mental health advocate. That's why his job as Chief Impact Officer of Better Up is a perfect fit.

The Duke of Sussex appeared at the startup's Inner Work Day on February 3 to talk to tennis champion Serena Williams and Better Up CEO Alexi Robichaud about how important mental health is to him and in general, and what else is important to her: her family.

"Serena hasn't sorted it out. None of us have sorted it out," said the Duke in a video shared by royal reporter Omid Scobie. 'Life is a discovery. And in that discovery, you find things you don't like, you find things you are uncomfortable with." [But in your efforts to avoid such things, suddenly all the stress and confusion, all the things that have been in your way in your life, whether in your personal life, your work life, whatever it is, your work-life balance, disappear, or by visualizing them, you can turn a negative into a positive and then those things will work for you. When you reach that point, from my perspective, it almost feels like a superpower, but it takes time and it's constant. It's ongoing." [One day it's great. I'm always beating myself up because nothing I do is working, and I'm always thinking, 'If I had done this and this and this, I wouldn't be in this situation right now.' So it's work. But it's the most fulfilling job we do, the most fulfilling job we get pulled into. ...... Except being a father." Oh.

In a clip shared on Better Up's Instagram page, Royal says, "Mental fitness is the pinnacle, it's what you're striving for. There's a reason it's called inner work, and immediately you're like, "Is this going to be more work?" I think some people shy away from it." Why?" It's like, "But if you understand inner work, outer work becomes so much easier.