HBO's Revealing New Robin Williams Documentary

Robin Williams: Come Inside My Mind fittingly starts out by showcasing how the comedic master's mind ricocheted at a dizzying velocity, bouncing around from character to character.

The new documentary, which premiered at Sundance earlier this year before airing on HBO on Monday, attempts to solve the mystery of that mind and what drove Williams throughout the years.

Filmmaker Marina Zenovich, who also made films about Roman Polanski and Richard Pryor, interviews several of his high-profile friends, such as Billy Crystal, David Letterman and Whoopi Goldberg, as well as his first wife, Valerie Velardi, and one of his children, Zak Williams.

Much of the film's two hours are narrated by audio clips from interviews with Williams.

The documentary doesn't dwell for very long on the exact circumstances around Williams's 2014 death. According to an essay from his wife, Susan Schneider Williams (who is not in the film), Williams had Lewy body disease and died from suicide "at the end of an intense, confusing, and relatively swift persecution at the hand of this disease's symptoms and pathology."

Instead, several people in the documentary note that the "sparkle had gone out of his eye" during the time Williams worked on his 2013 sitcom, The Crazy Ones. Crystal remembers seeing Williams for the last time when he revealed he had been diagnosed with Parkinson's disease. "When he told me, I never heard Robin be afraid except for that moment," Crystal says.