June 5, 2014 at 8:36 AM ET
Robert De Niro isn't one of the breed of celebrities who love to talk about their personal lives. But the tough-guy actor broke character when it came to his father, late artist Robert De Niro Sr., speaking to TODAY's Matt Lauer on Thursday about a new documentary about his dad.
"I just felt I had to (talk about him)," De Niro told Lauer. The actor reads from his father's journals in the film, "Remembering the Artist: Robert De Niro, Sr."
"The intention was to make a documentary about my father —because I owed it to him and all the family, because of the great work that he had done," De Niro said.
In the 1940s, De Niro Sr. was a young artist on the rise, known for vibrant colors and bold images, and his work was exhibited in elite galleries alongside the works of famous artists such as Jackson Pollock and Mark Rothko. But he struggled to keep up with the modern art scene as abstract and pop art became popular, and also suffered from depression. In a clip from the film, De Niro, Sr. once confided, "I feel that I have hardly the courage at this moment to wash my brushes, which have been standing in turpentine for days."
He later decided to reinvent himself in Paris, where his son tried to help promote his father's work. "Literally we would carry (the artwork) to the galleries in the Left Bank," De Niro recalled to Lauer.
The documentary also reveals that De Niro's father was a gay man in a time when that was much less accepted, even among artists.
"I could have talked to him about it," De Niro told Lauer. "I didn't feel it was right. That's his business."
The actor has kept his father's New York art studio untouched even 21 years after his father died. "I don't know, I can't let it go," De Niro told Lauer. "As long as I can afford to keep it, I will keep it."
His father lived to see his son succeed in Hollywood, and though he was proud of his offspring, it reminded him of his own lack of visible success in the art world.
"He didn't acknowledge it in a certain way, but he was resentful because, 'Why couldn't it have happened with me?' you know?" De Niro said. But his father also wrote of his pride in his only son: "Thank you, God, for Bobby's having turned out so well."
"He was proud of me," De Niro told Lauer. "He's not the kind of father to say, 'I'm proud of you, son.' ... In his way, he was proud."
"Remembering the Artist: Robert De Niro, Sr." airs Monday at 9 p.m. on HBO.