Joaquin Phoenix Says ‘I’m So Sorry’ for ‘Horrible’ and ‘Uncomfortable’ Letterman Interview: ‘One of the Worst Nights of My Life’

Joaquin Phoenix was the guest of honor on “The Late Show With Stephen Colbert” on Tuesday night, marking his first appearance on the late-night staple since his infamous 2009 interview with Dave Letterman and subsequent on-air apology the next year.

The Oscar winner memorably appeared on Letterman’s “Late Show” in character (shaggy hair, untamed beard and all) from his mockumentary “I’m Still Here,” which documented his life after the spoof announcement that he was retiring from acting to pursue a hip-hop career. The interview, some of which was used in the film, was incredibly awkward and led the public to believe Phoenix was having a mental breakdown.

Sitting down with Colbert, Phoenix said it was his intention to get a big reaction out of, not just Letterman, but the public at large. However, he said he did give the show a heads up.

“When I came on this show with Dave, I originally did the pre-interview in character and I realized that it was just a little silly, so I called them back and I said, ‘Listen, this is what I’m doing. I’m coming out here and I’m doing this whole thing. And I just want Dave to like, lacerate me. I just want it to be really dangerous,'” Phoenix said. “That was the kind of intention — I just always wanted to get this reaction and see how I would respond to that. So it was beneficial for no one to know, except when needed.”

But Phoenix admitted that the interview itself was “horrible,” adding: “It was so uncomfortable. I regret it, I’ll never do it again. I’m so sorry.”

After the two shared a laugh, Colbert told Phoenix, “I don’t know if [Letterman’s] watching.”

“He might be and I just need to say, I’m sorry,” Phoenix responded.

The actor, who stars in Ari Aster’s new movie “Eddington,” did apologize to the late-night host when he came back on “The Late Show” in 2010. “I hope I didn’t offend you in any way,” he said at the time. “You’ve interviewed many, many people and I assumed that you would know the difference between a character and a real person, but I apologize.”

Reflecting on the moment with Colbert, Phoenix concluded: “It was strange because in some ways, it was a success, and it was also just one of the worst nights of my life.”

Watch Phoenix’s full interview with Colbert below.