As with the deaths of Jim Henson, River Phoenix and Phil Hartman, Robin Williams’ hit me like a punch in the gut and left me speechless for a time. Here is a man whose work I had followed ever since I first saw him in Robert Altman’s “Popeye,” and we have always known his brain to work at 100 miles a minute. He was an extraordinary talent who kept us laughing hard as he managed to improvise routines out of what seemed like thin air. The fact we were now living in a world without him seems unreal even today, and there are times when I think August 11, 2014 should be designated as the day the laughter died.

Among the striking images shown in the first few minutes of “Robin’s Wish,” other than the beautiful vistas of San Francisco and Marin County, are images of newspapers, magazines and tabloid rags which pondered over why the Oscar-winning comedian committed suicide. Was it because he suddenly left a 12-step program where he was dealing with alcoholism? Was he in dire financial straits? Was he upset the show which marked his return to television, “The Crazy Ones,” was cancelled after only one season? Did he really never get over the death of John Belushi? Did all those years of drug and alcohol abuse finally catch up with him? In the wake of his passing there were many questions, and they eventually became rumors which spread like wildfires. As many sought to get to the truth, the rest of us felt so far removed from it.

The documentary “Robin’s Wish” is filmmaker Tylor Norwood’s attempt to set the record straight about what really happened to Robin Williams and why he died. It also serves as a deep examination of disease Lewy Body dementia (LBD) which may sound new, but has actually been around for many, many years. We also get a close and personal look at Robin’s last days before his tragic death, and it proves to be both very sad and yet hopeful all at the same time.

Instead of a full-fledged biography, Norwood looks specifically at Robin’s evolution as an actor and comedian. We see Robin talk about how the brain is “an extraordinary three-and-a-half-pound gland” and that he does not have an act as much as he does a “cesspool of consciousness.” He discusses his time at Julliard in New York where he got heavy duty training as an actor, and of how he left before he could have graduated and moved back to San Francisco to find acting work. When he couldn’t find any, he started doing stand up comedy in which he succeeded in, as one close friend put it, in “demolishing” every single audience he performed in front of. Back then, everyone was in awe of his talents as his mind moved at lightning speed, and this was only the beginning. Like them, we were in awe of what he could do.

Throughout, the documentary moves back and forth from his life to the subject of the LBD which, while it may pale in comparison to Parkinson’s, Alzheimer’s or ALS, can be every bit as debilitating and deadly. UCSF Professor Bruce Miller is shown describing it as a devastating disease which is fast and progressive and a killer. It also increases mental disorders such as depression, anxiety and insomnia, and paranoia and delusions are also major symptoms. There is no none cure for this disease as of yet, and it usually ends in suicide. But even worse, is often misdiagnosed.

Robin’s widow, Susan Schneider, did not have a name for what killed her husband until she read his autopsy report. Initially, Robin was diagnosed with Parkinson’s, but this was not the case. Susan says had Robin known what he was suffering from while he was alive, then he would have at least had some peace. As for Professor Miller, he described Robin’s case as being the most devastating case of LBD he had ever seen, and he was amazed the “Good Will Hunting” actor could move or walk at all.

As “Robin’s Wish” goes on, we see how LBD came to affect the actor long before he died, and it is devastating to witness the effect it had on his comedic gifts. Whether it was on the set of “The Crazy One” or the third “Night at the Museum” movie, he started to have trouble memorizing his lines and coming up with stuff to improvise. At one point, he tells someone how he is not himself anymore, and you feel his disassociation around everyone to an infinite degree. To realize you are not who you once were has got to be horrifying.

Learning about this mental disintegration from friends and colleagues such as Rick Overton, David E. Kelley and Shawn Levy helps to shed light on what Robin was going through as LBD was already taking its toll on him. To see someone lose gifts few are ever endowed with is painful, and it also reminded me of the last time he was a presenter at the Oscars. Whereas in the past he would come up with some hilarious thing to say or take aim at Jimmy Swaggart (“Remember, there is no such word as audit in the Bible, okay?”), he simply just listed the nominees and read the winner. Many wondered why he seemed so listless, and now we know.

Schneider deserves a lot of credit for being so open about Robin’s struggles as she still feels the pain of his death from day to day. The love they had for one another was very real, and we see the two of them at their wedding and in many pictures which illustrated just how close they were to one another. She also shares why the two of them had to sleep in separate beds at one point as Robin’s insomnia worsened to where he woke up at early hours and accidentally injured her.

“Robin’s Wish” does make a solid case for how serious a disease LBD is, and after watching the documentary there is no doubt this is what killed him. It makes clear what a wonderful soul he was as he took the time to meet with soldiers who were wounded, children who were sick and others who needed a laugh during a dark time in their lives. It also makes clear of the fact Robin was clean and sober at the time of his death. Drugs and alcohol did not rob us of him.

If there is anything I feel is left out here, it is the thoughts and feelings of others close to Robin such as his children or his ex-wife Marsha Garces whom he was married to for 20 years. Their absence here makes me wonder how they feel about all of this. Perhaps they were not invited to participate or chose not to. Even though this is not meant to be a full out biography of Robin Williams, it feels like some pieces are missing which would have made this portrait more complete.

“Robin’s Wish” is not the easiest documentary or movie to sit through as we know how it ends. The void the famous comedian and actor left in his wake is still deeply felt all these years later, and it is impossible not to feel bad for his closest friends. This is especially the case for the one friend who was informed of Robin’s death over the phone by a reporter who said he died by suicide. This is not the way to inform someone of their friend’s passing.

Nevertheless, as sad as “Robin’s Wish” may seem, it also filled with hope. As debilitating as LBD was for him, he fought it like a warrior even if he did not know exactly what he was fighting. We are also reminded of his perspective on life which he earned through a lot of life experiences and mistakes he learned from. To him, life was always about other people, and he simply wanted to make everyone feel less afraid. Norwood definitely finds the right note to end this documentary on as, while Robin may be gone, he shows we can still carry on his legacy from one generation to the next. No one who knew Robin Williams will ever forget the impact he had on others, and no one ever should.

* * * ½ out of * * * *

Click here to find out how you can donate to the Lewy Body Dementia Fund of the American Brain Foundation.