In the upcoming PEOPLE and ABC special People Icons: Gone Too Soon, Williams' widow Susan Schneider Williams opens up about the "quiet, intellectual man" she knew and loved


There were two sides to Robin Williams.

In the upcoming PEOPLE and ABC special People Icons: Gone Too Soon, Williams’ widow Susan Schneider Williams opens up about the “quiet, intellectual man” she knew and loved — a far cry from the explosive personality often seen on screen.

“The Robin that I knew was not the crazy, manic one who would be performing on stage for comedy or sometimes in his roles as an actor,” she says in an emotional interview for the special, which airs on Tuesday at 10 p.m. ET on ABC. “And I think that’s commonly a misconception, is that Robin was always running at that speed. And that is not the man that I knew. That’s not the man I fell in love with.”

Instead, Williams describes her late husband as an “observational genius” who used his private time to conserve his energy for his comedic performances.

“Robin was a quiet, intellectual man, sometimes playful. But primarily what moved him was the fact that he was an observational genius,” she says. “And if you can imagine the energy that he would bring to the stage — no one can do that full-time. And I think the brilliance behind that impact of energy he would bring was because in his time off, he was someone who was contemplative and an observational genius.”

Robin died by suicide in August 2014 at age 63. It was only after an autopsy following his death that his family learned he had Lewy Body Dementia, a horrific and baffling disease that causes disorientation and hallucinations – among numerous other heartbreaking symptoms.

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And while Robin is largely remembered for his iconic movie roles, Williams says his real impact is yet to come.

“Robin’s real legacy will unfold in the decades to come and really shed light on brain disease as a whole, but particularly dementia, which 47 million people worldwide are suffering right now,” says Williams.

“And for [other Lewy Body Dementia patients] to know that they are not alone, that this is what Robin Williams had and they’re being heard, they’re not outcasts. So the way I see it, he truly is on that back nine going, ‘I got this,’ where he made people feel not alone before. They don’t have to feel alone now.”

People Icons: Gone Too Soon, which looks back on the lives of beloved stars, also features exclusive interviews with Patrick Swayze‘s widow, Lisa Niemi; Prince‘s sister, Tyka Nelson; and Whitney Houston‘s friend BeBe Winans.