When Robin Williams died in 2014, fans around the world grieved the beloved entertainer, but for his son Zak, it took a while before he could privately process the emotions he felt about losing his dad.
Williams, who is a mental health advocate, opened up about his grieving process in an interview with Oprah and Prince Harry on Apple TV's "The Me You Can't See."
Harry asked Zak about how he felt seeing so many people around the world mourning his father as though they knew him, something Harry also experienced when his mother Princess Diana died.
"From my end it was hard to separate initially the process of privately grieving versus sharing the grieving with the general public, both the American public and the world," Williams said.
Williams said the challenge of differentiating between the public and private grieving process took a toll on his mental health.
"I found myself extremely emotionally disregulated and feeling vulnerable and exposed when I wasn't ready to be vulnerable," he said. "And that created a major challenge for me."
Williams said he eventually realized he needed to take some time for himself.
"From my end, I didn't get a chance to focus on the private grieving process until about a year and a half after my dad passed away, meaning that I didn't recognize that I needed to grieve privately," he said. "I am very thankful and appreciative that I did recognize how to set boundaries."
Williams continues to honor his father by working with Inseparable, an organization advocating for accessible and affordable mental health care for all Americans.
On the sixth anniversary of his dad's death last year, Williams posted a photo of his father, along with a message.
"Dad, today marks six years since your passing. Your legacy lives on in your family and in those who carry your spirit within their hearts," he wrote. "We will continue to fight for what’s good in the world, for peace, and for connecting people instead of tearing them apart. Love you so much!"
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