The Duke of Cambridge has said he felt "pain like no other pain" after his mother, Princess Diana's death.
Prince William did the enlightenment in a BBC TV documentary on mental health.
He said the "British stiff upper lip thing" had its place when times were difficult, but people also needed to "relax a little and be able to talk about our feelings because we are not robots".
William also talked about how to act as an air ambulance pilot that made him feel that death was "just around the door".
He said he was dealing with the loss of his mother – who died in a car accident in 1997 – thought he felt he could relate to others who had suffered a misunderstanding.
He said, "I've been thinking about this a lot, and I try to understand why I feel I'm doing it, but I think when you are deprived of a very young age, preferably preferably, but especially at a young age, I can reason Close to that, you feel pain like no other pain.
"I felt that with some jobs I did, there were special personal resonances with the families I was dealing with," he said.
He described how the emotional aspect of being a pilot in the East Anglian Air Ambulance was "difficult", especially after coming from the military where emotions tend to be set aside.
He said the ambulance world was "much more open" and he talked about experiencing "very raw, emotional daily things where you work with families who have the worst news they could ever have on a day to day."
"The raw feeling … I could feel it brewing up in me and I could feel it would take its toll and be a real problem. I had to talk about it."
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In the BBC One documentary to be screened on Sunday, William speaks to football player Peter Crouch and Danny Rose, ex-player Thierry Henry and Jermaine Jenas, and England's manager Gareth Southgate.
They shared all the different psychological problems and pressures they encountered in their careers.
William and his brother, the Duke of Sussex, have previously talked about their mother's death – when they launched a mental campaign called Heads Together, which encouraged people to talk more openly about their problems.
The Duke and Duchess of Cambridge and the Duke and Duchess of Sussex also collaborated last month to launch a text messaging service for people experiencing a psychic crisis.
William, Kate, Meghan and Harry have backed the initiative, called Shout, by $ 3 million from their Royal Foundation.
The charity war Shout also received a £ 1.5 million grant from BBC Children in Need.
A Royal Team Talk: Managing mental health is broadcast on Sunday, May 19, at 22:30 on BBC One.