Monday marked the 23rd anniversary since Princess Diana died in a car crash at the age of 36. In the wake of this tragic occasion, a clip has resurfaced in which her son Prince Harry expressed regrets over his brief final phone call with his mother.

Fox News reported that Harry and his older brother Prince William were just 12 and 15 respectively when Diana passed away. Harry talked about his last phone call with her in the 2017 documentary “Our Mother Diana: Her Life and Legacy.”

In the film, Harry explained that he and William were so distracted playing with their cousins at the Queen’s Scottish retreat Balmoral when Diana called that they actually cut the conversation short.

“If I’d known that that was the last time I was going to speak to my mother the things that I would – the things I would have said to her,” Harry said.

Later in the documentary, Harry revealed that he had only cried about Diana’s death at her graveside on Sept. 6, 1997, and “maybe, maybe once” since then.

“So there’s, you know, there’s a lot of — there’s a lot of grief that still needs to be let out,” he said. “There’s not a day that William and I don’t wish that she was still around, and we wonder what kind of a mother she would be now, and what kind of a public role she would have, and what a difference she would be making.”

William agreed with his brother’s sentiments.

“We won’t speak as openly and as publicly about her again,” William said at the time.

This comes after royal expert Tina Brown said that the impact of Diana’s death combined with the unclear role of being the second royal son has made Harry “an unhappy man.”

“I think the deep wounds of his mother’s death have never healed,” Brown told the New York Times back in February. “And his sense of his role as the second son, the fact that he loved his military career but then left and didn’t have that sense of purpose — all of that came together to make him a very unhappy man.”