For Joaquin Phoenix, all the world truly is a stage.

The "Inherent Vice" actor is known for his infamous 2009 "Late Show" appearance, in which he performed a bizarre form of method acting during his interview with David Letterman. He later revealed that it was all an act to promote his "I'm Not Here" mockumentary. But now Phoenix has done it again, and he pranked the Internet this time.

On Monday night, Phoenix appeared on the "Late Show" and told a crazy story about an intense yoga instructor, who he later revealed to be his fiancée. "I think she's the one," Phoenix told Letterman rather convincingly. "I proposed to her, and she said yes." On Tuesday morning, numerous media outlets began reporting that the actor was engaged and offering him congratulations.

When Phoenix appeared on "Good Morning America" on Tuesday, however, he admitted that the whole story was made up. "I think my life is so boring and it seemed like something exciting to talk about," Phoenix said.

But Phoenix doesn't view his made up story as a "prank" necessarily. While appearing on "Live! With Kelly and Michael" shortly after he told them that Letterman wasn't fooled. " I did not play a prank on him - he knew that I was joking around," Phoenix said. When asked about his "Walk the Line" and "Inherent Vice" co-star Reese Witherspoon, the actor joked that they are engaged as well. This man really cannot be trusted (but we love his hoaxes anyway).