Joaquin Phoenix – who has recently said he was quitting acting to become a rapper – was on Letterman last night. And it was probably the most awkward, strangest interview in the history of such things.

Contrast that with a previous appearance on Letterman.

There’s been lots of speculation that Phoenix’s career switch is a hoax, mainly because of his bizarre attempt at rapping recently in Las Vegas.That and the fact that his brother-in-law Casey Affleck was documenting the whole thing for some sort of documentary. I’m not so sure – he seems really gun shy and completely lost on Letterman. I think something inside this guy’s brain has snapped. Then again, he is a great actor.