If you weren’t alive when Diana Spencer, Princess of Wales, made her iconic mark on the world, a new HBO documentary will make you wish you were. It will also make you weep the way so many did the weeks following her tragic passing. The film, which commemorates the 20th year since her premature death, is called “Diana, Our Mother: Her Life and Legacy.”

Prince William and Prince Harry — you know, second and fifth in line to the British throne — along with William’s wife Catherine, the Duchess of Cambridge, started Heads Together, an initiative that joins eight charities to destigmatize what they believe is the center of many issues of concern: mental health.

In a video posted in April, the trio sat on a picnic table in a picturesque Kensington Palace garden speaking about why they felt mental health was a common thread between the areas the three royals were working in, including homelessness, military, addiction and, of course, bereavement.

“Harry and I, over the years, have not talked enough about our mother,” William said in the video.

Harry agreed, “No, never enough.”

Harry in particular has admitted to locking away his feelings, with therapy being essential to releasing his pent-up grief.

This YouTube video, and the events that followed — including their charity being represented by 700 runners in the 2017 London Marathon — served as a preface to the honest documentary that was unknowingly and eagerly awaited for 20 years.

William and Harry were only 15 and 12 years old respectively when Diana, 36 at the time, passed away in a car accident Aug. 31, 1997.

The documentary opens to the pair looking over a family photo album. William shows Harry a photo of Diana holding the elder son while pregnant with the younger.

“Believe it or not, you and I are both in this picture,” William said as Harry looked on.

Photos of the young boys with their mother — the boys dressed in matching outfits and looking unabashedly happy — flash on the screen as Harry’s voice fills the quiet: “This is the first time that the two of us have spoken about her as a mother.”

The viewer is then taken back to the ‘60s and Diana’s childhood. Her brother, Charles Spencer, and longtime friends speak candidly about the woman they knew, with photos and videos of her accompanying their anecdotes. They speak about a girl with infinite potential.

Then began her marriage to Charles, Prince of Wales, and a nervous feeling persists. Thoughts of alleged affairs Charles had with his now-wife Camilla, Duchess of Cornwall, and rumored disagreements between Queen Elizabeth II and Diana hang heavy in the air. One wonders if they will address the darkness that hid behind the smiles captured by royal photographer Jayne Fincher. Curiously, William and Harry do not mention their father or grandmother throughout the documentary.

After a moment, these feelings have no choice but to stand second to the light shed on Diana’s work as an activist. Diana shaking the hand of an AIDS patient shook the world in 1991 and made strides to end the stigma as soon as the photograph was printed.

Following her divorce from Charles, she is removed from the royal family, but it is impressive how she turns the world’s attention to her latest and last fight. Three weeks before her deat, she was in Bosnia, working to outlaw land mines throughout the world. The film shows Harry continuing this legacy in 2017.  

We almost forget this is a documentary about a person who has passed away. We root for her, her role as an activist and her responsibility as a divorced parent. We hope her calamitous run-ins with the ever-malicious paparazzi end in a tennis racket to the face.

Her sons, now men, cast a shadow of regret as they recount their last phone conversation with their mother.

As the voice of a reporter is heard in the distance, saying, “The Press Association announced with a newsflash at 4:41 that Diana, Princess of Wales, has died …” there is as little warning about her death as there is for the tears that come.

Imagine a parent has died, and the public has made a living in pursuing and publishing fabrications that surrounded the car accident in Paris on August 31. The documentary is a simple piece that connects us with a woman we never knew by way of the children she left behind, wondering when someone will ever shake the world like she did again.