Joaquin Phoenix will appear once again on The Late Show With David Letterman on September 22 to promote the new documentary, of which he is the focus, I’m Still Here. Normally, this isn’t news. Celebrities go on talk shows all the time to promote their projects. What makes this appearance special? Well, his last visit was one of the most bizarre appearances on a talk show by anyone. Ever. If you ever needed a reason as to why David Letterman is a comedic genius, watch the interview. His remarks and retorts are brilliant. Check out the video below.