*ahem*. Numenor is ATLANTIS. Yes, that means Aragorn's people are Atlanteans. Sauron used to be able to have forms like Gandalf and Saruman, but he was kind of on Numenor when it sank and lost the ability to have a 'human' form. And Sauron was a flunky (well, a lieutenant) of the actual Big Bad. (Also, he was originally - in the sense of the evolution of the stories from their earliest form - a giant cat. Go figure). Also, Tolkien in his later years apparently hated the idea that the world was actually 'flat' at one point, and worked on reconstructing the mythology - but it was hampered by the fact that, if it was falsehoods created due to mythology evolving over time, there were elves who were there from the beginning who would've known better.