Speaking at the launch of the Mental Health at Work campaign in Bristol, England, in partnership with Heads Together and the Mind mental health charity, the Duke of Cambridge reveals he sometimes struggled after coming home from his job.
Following his Heads Together campaign in partnership with the Duchess of Cambridge and the Duke of Sussex, the royal launches his new initiative to change the way United Kingdom employers look at mental health in the workplace.
The "Mental Health At Work" initiative is an online portal that will provide employers with the resources and tools they need to better support their staff.
He said: "It gives me the opportunity to get the guys to talk to one another, and to talk to me, and then recognise, that if they have got a problem, they're not on their own".
He will visit Bristol's Engine Shed to meet people already benefitting from the online gateway.
William added: "If you see sad things every day, you think all life is like that, you're just seeing all the sad things, all the pain every day".
It comes as new figures revealed nearly half of all United Kingdom workers had experienced poor mental health in their current job.
Mental Health at Work is one of the initiatives being driven by William as part of his ongoing work with Heads Together.
The survey revealed only half of those who had experienced poor mental health had talked to their employer about the issue, suggesting as many as one in four United Kingdom workers is struggling in silence with problems such as anxiety, low mood and stress.
He said that while working as an air ambulance pilot crews were encouraged to talk about problems. He is so calm and approachable.
The senior paramedic, who developed PTSD following some of her experiences at work, added: "I've always held the belief that everybody is susceptible to mental health problems and I wouldn't expect even a member of the royal family to be exempt from that".