File photo of actor Robin Williams arriving for the European premiere of "Happy Feet " at the Empire cinema in London
Actor Robin Williams arrives for the European premiere of "Happy Feet " at the Empire cinema in London in this file picture taken November 26, 2006. Oscar-winning actor and comedian Williams was found dead on Monday from an apparent suicide at his home in Northern California, Marin County Sheriff's Office said. He was 63. REUTERS/Luke Macgregor/Files

Robin Williams' secret battle with depression that drove him to suicide is still hard to believe for many, as the comedian never showed signs of loneliness. Barry Levinson, director of "The Humbling" has said that Robin Williams, 63., was a great person and that his comedic skills were beyond measure. This is why he feels bewildered by the actor's death.

Barry Levinson has directed four of Robin William's successful films. At the press conference of "The Humbling," according to The Hollywood Reporter's [THR] report, the director took a few moments to reflect on Robin Williams' death.

"None of us will understand what really happened. He was brilliant and sensitive in ways that were extraordinary. He could be comedic in ways that I don't think we can define," the director said.

Working with Robin Williams was a one-of-a-kind experience for the director. Robin was said to be passionate about his craft as well as he cared about other people.

"If I can go back to Good Morning Vietnam, we had some sequences where we were dealing with the Vietnamese and they couldn't really do the scene as written," Levinson said, as quoted by THR. "Instead of trying to make it work that way, we did improvs with it."

"His interest in the people was so fascinating that he was able to pull out their behavior and how they thought and functioned, which really brought a life to Good Morning Vietnam, up and above what the story was. He has an enormous passion for people and a great sense of humanity and was an extraordinary human being," THR quoted Levinson as saying.

This is not the first time Barry Levinson has talked about Robin Williams after he committed suicide. He has written a column in the Variety, sharing how he feels about Robin's death. For him, the comedian's suicide showcased "his deep feelings for life." Because he felt too much, he hurt too much as well, enough to take his own life.

The director writes that Robin was a rarity in this world, one of the "endangered species." Robin was described as too inquisitive and yet too vulnerable, thoughtful yet too innocent. The director felt that the comedian was too delicate for the harshness of this world. For the director, when Robin died, the world did not just lose a great actor and a comedian, everyone lost a friend.