Staring directly down the camera lens in a newly released video, Prince Harry told viewers: 'I couldn't remember my mum's laugh. I couldn't remember what she looked like.'

The heartbreaking admission was made during the trailer for his new series with American education platform MasterClass, titled Redefining Grief: Building Resilience Through Loss.

The 20-part online class, available to paying subscribers only, features Harry discussing candidly how he 'slipped into depression' following his and Meghan's high-profile departure from Britain in 2020.

It also reveals even further details about his journey with trauma and PTSD that he's suffered from since his mother's tragic death in 1997.

Over the years, the troubled prince has been remarkably open about his rocky mental health, revealing in a 2017 interview on the 20th anniversary of Diana's death that grieving in the public eye had left him 'very close to a complete breakdown on numerous occasions'.

But Harry's most detailed account of the long-running battles in his mind comes from his controversial memoir Spare.

In it, he regularly mentioned his struggles at being the second-born son, describing how his position as Prince William's junior left him bubbling away with resentment, writing: 'I was the shadow, the support, the Plan B. I was brought into the world in case something happened to Willy.

'I was summoned to provide back-up, distraction, diversion and if necessary, a spare part. Kidney, perhaps. Blood transfusion. Speck of bone marrow.'  

After all, their hierarchy was baked into his life from the beginning, as even at nursery, the royal children were all treated differently depending on their hereditary pecking order. 

Harry also recalled his school days at Eton College, where he would spend late nights at school smoking weed and wandering the school halls 'lonely and homesick, probably anxious and depressed'.

Unlike William, who excelled at school, Harry struggled academically, with one of his former teachers describing him as a 'weak student'. 

His lack of strength in the classroom made him stand out in Eton's highly intellectual environment. 

In her 2022 book The Palace Papers, author and Diana confidant Tina Brown wrote that Harry 'regularly got into fights that turned physical' at Eton, even on one occasion needing to use crutches after 'kicking in a window during a dispute with another student over a girl'.

Harry claimed that his memory was bad because after his mother's death he 'didn't want to fix it, because memory equalled grief'. 

After scraping just a B and a D for his A-levels, he was admitted into the prestigious military academy Sandhurst to begin his career in the British Army – an experience which he would later tell The Mail on Sunday was 'the best escape I've ever had'.

Away from the stuffiness of Eton and the glare of the paparazzi, Harry said he was able to gain a 'deep understanding of all sorts of people from different backgrounds', and finally 'felt I was part of a team'.

He completed his training in 2006 and was poised to go on a six-month tour of Iraq until he was pulled out at the last minute because he was deemed a high-risk target. 

Perhaps understandably, the sudden end of Harry's military escape from his hated role as William's second fiddle caused him fresh agony. 

Friends of Harry would later tell writer Katie Nicholl that he yet again 'slipped into a state of depression' after hearing the news.

It was during this period that Harry would embark on one of the most volatile periods of his adult life, featuring some of his most well-publicised controversies and media spats.

Anointed as the 'party prince' by the press, Harry became a permanent fixture of the front pages due to his frequenting of Mayfair nightclubs. 

In Spare, he describes turning to 'vodka and Red Bull' for comfort after his army disappointment and was often seen getting into fights on nights out.

'Without his army mates to cut him down to size, his sense of entitlement was out of control,' according to Brown. 

His outbursts became more frequent and childlike, with the prince revealing he took up boxing because he was always 'on the verge of punching somebody'.

He took his anger out on clashes with the paparazzi, something that would go on to be a defining feature of much of his adult life, with Harry claiming that the sounds of shutters clicking triggered his PTSD. 

'That click, that terrible noise, from over my shoulder or behind my back or within my peripheral vision, had always triggered me,' he said in Spare. 'After Sandhurst it sounded like a gun cocking or a blade being notched open.'

Harry would eventually go on to see action in Afghanistan in 2012, but not before he made headline news after pictures of him naked in a hotel suite in Las Vegas were leaked shortly before he was due to fly to Helmand. 

He famously brushed off the incident, claiming it was because he was 'too much army and not enough prince', but beneath the party-boy surface, the prince was struggling.

After returning from war, Harry would suffer from symptoms of PTSD himself, although he pointed out that it may be associated with his mother's death as much as it was Afghanistan. 

'Despite all my work with wounded soldiers... it never dawned on me that I was a wounded soldier,' he said. 'And my war didn't begin in Afghanistan. It began in August 1997.'

Harry would later raise eyebrows among some in the veteran community when he was accused of boasting in Spare about killing 25 Taliban fighters from Apache helicopter gunships, as detailing the killings could have potentially triggered veterans suffering from PTSD.

Nevertheless, according to Harry's account, his transition from a soldier to a full-time working royal was one littered with anxiety and depression. 

'By the late summer of 2013 I was in trouble, toggling between bouts of debilitating lethargy and terrifying panic attacks,' he recalled.

'Hours before a speech or public appearance I'd be soaked with sweat. Then, during the event itself, I'd be unable to think, my mind buzzing with fear and fantasies of running away.'

It was around this time that Harry was dating Cressida Bonas, who would be his last serious relationship before he met Meghan.

She played an important role in bringing Harry's bubbling rage down to more of a simmer by forcing him to confront his underlying issues. 

According to Brown, it was Cressida who first persuaded him to see a therapist, which caused him to seek advice from MI6 to find the right person. 

Cressida understood the historical reasons why Harry hated journalists but believed that he should, like his brother William, come to terms with his royal status. 

In Spare, Harry wrote how it was Cressida who he cried to about his mother – for the first time since she died when he was 12. 

'Wiping my tears, I thanked her. She was the first person to help me across that barrier, to help me unleash the tears. It was cathartic, it accelerated our bond, and added an element rare in past relationships: immense gratitude,' he wrote. 

'I was indebted to Cress, and that was the reason why, when we got home from Kazakhstan, I felt so miserable, because at some point during that ski trip I'd realised that we weren't a match.'

After their relationship ended in 2014, Harry would be single until he met Meghan two years later.

Although his rivalry with William had dominated Harry's life so far, he began attending therapy sessions at his brother's behest.

It was something which he would later thank him for, saying his brother had been 'a huge support' by getting him to seek help.

In his 2021 book, Brothers and Wives: Inside the Private Lives of William, Kate, Harry, and Meghan, writer Christopher Andersen said that therapy, along with his newly created Invictus Games, meant Harry finally 'felt he was conquering the panic attacks that had plagued him in recent years'. 

Harry also seemed to find comfort through sport, with Anderson claiming that organising the Invictus Games was Harry's 'one hundred per cent a cure for myself'.

Following the success of the Invictus Games, Harry, Will and Kate would go on to launch the mental health charity Heads Together, in which they would deliver a joint speech encouraging people to open up and speak about their problems. 

But sadly, the joint effort between the brothers wouldn't last long, beginning to sour quickly after Harry married Meghan. 

Infuriated by press coverage of his wife, he said that he went to a 'very dark place' and felt that 'he didn't have anywhere to turn to'.

The pair would release a statement featuring a scathing attack on the British press for the 'bullying' and 'relentless propaganda' surrounding Meghan and said that he was scared of his 'wife falling victim to the same powerful forces' that his mother faced.

Then they infamously quit the Royal Family and moved to California in March 2020, from where they would continue to attack his brother and the family that he previously credited with helping his mental health.

Despite always being critical of the press, Harry seemed to relish his newfound freedom, taking to the airwaves to deliver blow after blow to the family he felt had wronged him. 

In an explosive TV interview with Oprah Winfrey, Harry astonishingly claimed that his father Charles had cut off all communication with him after leaving The Firm and said that 'my family literally cut me off financially'.

He said he had to leave the family for 'my own mental health, my wife's, and for Archie's, as well, because I could see where this was headed', before adding that his wife Meghan had 'saved' him.

The disillusioned prince also took aim at William, claiming that the two were 'on separate paths' and that his brother was 'trapped' in the UK by the Royal Family.

He would go further two years later in Spare, where he said that William had called him 'brainwashed' and that the two had a 72-hour argument over text from different sides of the Atlantic. 

'I realized that my worst fear was coming true,' Harry wrote. 'After months of therapy, after working hard to become more aware, more independent, I was a stranger to my older brother. He could no longer relate to me — tolerate me.'

The book made it clear to royal fans how acrimonious the rivalry with William was, and how it had festered inside Harry.

Many of the stories in the book seemed to be designed to make the public think less of his brother, none perhaps more so than the damaging claim that William had physically attacked him by pushing him into a dog bowl.

Spare also revealed that, as well as William, Harry also put the blame for his problems on his father, Charles.

In one area of the book, he takes aim at the King's alleged coldness, writing: 'Pa and I mostly coexisted. He had trouble communicating, trouble listening, trouble being intimate face-to-face.

'On occasion, after a long multi-course dinner, I'd walk upstairs and find a letter on my pillow. The letter would say how proud he was of me for something I'd done or accomplished.

'I'd smile, place it under my pillow, but also wonder why he hasn't said this moments ago, while seated directly across from me.'

According to Prince Harry, his royal upbringing caused him to suffer from 'generational trauma'.

Fast-forwarding through many of Harry's other snipes at his family from across the pond, and he and Meghan are now back in the UK following their decision to send Archie and Lilibet to school in Britain.  

But could Harry's new MasterClass course finally help him turn the page on his long-running feud with his family?

After all, it promises to show how he has discovered 'new ways to process grief and loss so you can find your way back to you'.

If true, the programme could finally unburden Harry of his family grudges, something other therapy has seemingly failed to do. 

In fairness, there seems to have been some progress over the summer, as Harry, Meghan and their children met with Charles and Camilla for a private meeting at Highgrove.

It all seemed to go well, but Harry and William still haven't met since they have both been in the UK, and they're understood not to have spoken in several years.

Harry's latest admissions in the Masterclass remind us he's now spent years telling the world about his pain.

Whether he can now leave it behind is a question only he can answer, but his estranged brother may be in no hurry to listen.