I saw my first clips of Star Wars (which I had never heard anything about before) on the popular science show Tomorrow's World (an item about the motion control cameras I think) and thought that the Rebel Base control centre was inside an X-Wing hurtling down the Death Star trench (too much Doctor Who I guess, I must of thought they were bigger on the inside).
I also thought Threepio was a guy in a suit of armor.
I read the comic book adaptation of Star Wars before seeing the film but I didn't read it right which was odd because I was normally very particular about words and had quite a high reading age at 7.
I thought Ben used to be called Ob Van Kenob and he was helping the Rebel Lions for about a month.