February 2009. Legendary late-night talk show host David Letterman introduces his next guest: Oscar-nominated actor Joaquin Phoenix. He’s sporting an unkempt beard, dark sunglasses indoors, and behaving like it was his first talk show appearance rather than his hundredth. Even Letterman, who could improv with the best of them, struggles to keep up with Phoenix’s short answers, insisting that he was done with acting so he could focus on becoming a rapper. Turns out, it was an attempt at viral marketing for the upcoming mockumentary, I’m Still Here. Okay, so maybe the interview didn’t tell us much about the movie or drive anyone t to see it, but it did tell us a lot about Joaquin Phoenix, the person and the performer, his deep commitment to his art form, and his obsession with authenticity that brought him through a difficult upbringing and into a wildly successful acting career.