Cannon tells us that 3PO has been in operation for a great number of years by the time Ep4 rolls around. It also says that he is one of the few droids never to have had his memory erased. So why is it that he doesn't remember Tatooine or Obi-Wan. I know people will say "Well those parts of the story weren't written when Ep4 was made" but we do know George had all nine parts "roughed out" before he made the original. Thoughts?