I'm not asking why you think it doesn't exist or other general cynicisms I'm asking what you think of the idea and general belief. I'm also asking about the concept as a whole not just the apocalyptic Planet X stuff.
EDIT:
Have to say as I led a lot of people to misunderstand, that I'm asking about Nibiru in terms of it as a concept. As in what do you think of the idea of Gods/Kings being from another planet? Or what do you think of the fact that the Sumerians were well ahead of their time but were absorbed by other cultures incredibly quickly despite it being a relatively barren place? I didn't mean to spark so many debates over the apocalypse etc.