The Queen is… well, the queen of smiling and waving, isn’t she? I realised this as I watched her at her Platinum Jubilee, standing on the balcony of Buckingham Palace, despite the obvious discomfort of her 96 years.

There is a tendency among younger generations – and I include myself in this – to see the Royal family as symbols of the repressed stiff upper lip that has been such a barrier to good mental health in this country. 

But my mind changed as I watched The Unseen Queen, the incredible BBC documentary narrated by the monarch herself, featuring previously private home footage of Her Majesty as a child and young mother.

As I watched her skip through the fields of Balmoral and gulp back a cup of tea almost as big as her 10-year-old head, I realised that the Queen isn’t buttoned up. She’s just – in the parlance of Instagram influencers everywhere – boundaried. 

I’ve watched it several times now and, on each occasion, I am struck by a sort of lightning bolt of spiritual enlightenment: the Queen has more to offer us in terms of life advice than any of the self-appointed wellbeing gurus who now litter social media and popular culture.

It’s all there in this 76-minute documentary, a veritable treasure trove of guidance for those feeling slightly adrift.

Here she is on raising children: “As with any team, there is strength in combination”; and here she is on the importance of inclusivity, way back in 1947 during her first visit to South Africa, long before any of us understood the concept of “woke”: “We share the same world, but we do not share the same opportunities. A tolerant society actively develops the people that belong to it, and enriches their lives because it values their diversity.” 

Here is a woman who could have got lost in glitz and glamour, but who instead shares the qualities of all great spiritual leaders, from the Dalai Lama to the Pope: she knows that no one person is better than any other and that she is but a vessel for something far bigger than herself. 

“We are all visitors to this time, this place,” she says at one point during the film. “We are just passing through. Our purpose here is to observe, to learn, to grow, to love. And then we return home.”

The Queen talks of faith in the future and the need to remove fear and in just a few simple words she passes on a message that spiritual teachers such as Eckhart Tolle and Deepak Chopra have dedicated their entire lives to spreading. 

“I have lived long enough to know that things never remain quite the same for very long.” Queen-speak, that is, for the most Instagrammable quote of all: This too shall pass. 

I was touched by her sentiments on doing service for others – another concept that is crucial in the treatment of addicts. 

“We sometimes think the world’s problems are so big that we can do little to help,” she said. "On our own, we cannot end wars or wipe out injustice. The cumulative impact of thousands of small acts of goodness can be bigger than we imagine.”

And when she talks of her late husband, the Duke of Edinburgh, she may as well be summing up the key to life: “His sense of service, intellectual curiosity and capacity to squeeze the fun out of any situation were all irrepressible.” 

I had not thought of the Queen as a mental-health icon before, but now I cannot stop. Long may she smile and wave over us.