This is the central point of the character to me. If Clark is not real, if Kal El has no psychological or emotional need that is fulfilled by being Clark, then there is no point to Clark existing in the first place. He has to be at the Planet because he wants to be there, because being a reporter and having the trappings of a normal life fulfills him in a way being part of the Justice League and saving the galaxy doesn't. The entire premise of Superman as a character falls apart the moment Clark Kent is dismissed as not being 'real.'