Prince William recently shared in a new mental health interview that he felt 'pain like no other' when his mother, Princess Diana, died.

In a documentary by BBC, the royal talked about how the British, especially the men, ought to find ease in speaking of mental health concerns. He also spoke about how deeply pain can be felt when one is "bereaved" while still at a tender age. The Duke of Cambridge confessed to having felt that way, saying he could "resonate closely" with an experience like that in his life.

The Duke was speaking of the death of his mother Diana who he lost while he was yet 15 years old, when she died in a tragic car crash, after being hounded by paparazzi.

He described his "pain" as one "like no other," something he said was hard to think could be equaled or even surpassed later on in life. Prince William pointed out that British men are particularly "nervous" about their emotions, and there are times that the sense of embarrassment over such feelings comes over. He termed this as the characteristic "stiff upper lip" of the British.

And while he said that that behavior was sometimes warranted for moments that seem "really hard," he shared that sometimes "we've got to relax" if just a "little bit." He pointed out that it was important that emotions are spoken about and shared, because, he says, "we're not robots."

In the clip, England's Duke of Cambridge encouraged "greater openness" about emotional health in his talk with soccer players, which was a part of his efforts in producing a film with BBC called "Royal Team Talk," which centers on mental health.

This talk was delivered to England team's soccer players Thierry Henry, Peter Crouch, Jermaine Jenas, and Danny Rose, as well as the team manager, Gareth Southgate.

The death of his mother in 1997 had not only greatly affected Prince William, and his only sibling, Prince Harry. The Princess of Wales had been a much-loved and respected figure. If the public which had worshipped and adored her worldwide had felt the grievous loss at her sudden passing, it is cannot be imagined what the young William and Harry had gone through during those times.

The two royals, who have always been very close, another of their precious mother's legacy, have in the past been very involved in mental health causes. William had spearheaded the creation of a website which focused on bettering work place mental health issues.

He had also been vocal about his criticism of English football clubs all over the country and how those have downplayed the issues on mental health of their players.  

The BBC One special A Royal Team Talk can be viewed Sunday at 22:30 hours.