J oaquin Phoenix has apologized for his controversial 2009 appearance on The Late Show with David Letterman. Phoenix, in character for his role in the mockumentary I'm Not Here, answered Letterman's questions with mumbles and one-word answers, leaving the host and the audience confused.

J oker star Joaquin Phoenix recently returned to The Late Show after a whopping 15 years — but something else also happened: he apologized for his infamous David Letterman interview from 2009 that took place on the show before Letterman turned the reins over to Stephen Colbert.

The actor was promoting the mockumentary 'I'm Still Here' when he delivered one of the strangest interviews ever recorded for late night television.