Joaquin Phoenix Apologizes to Letterman

It's been over a year since Joaquin Phoenix's bizarre appearance on the "Late Show with David Letterman" -- and the actor returned Wednesday, clean-shaven and sane, ready to apologize for his behavior.

"I mean, I think that you've interviewed many, many people and I assumed that you would know the difference between a character and a real person," Phoenix said about his now infamous interview, which turned out to be all an act for his fake documentary "I'm Still Here." "I hope I didn't offend you in any way," he added.