Some such stories are as follows:
The Horse and his Boy, C.S. Lewis (1954)
The Prince and the Pauper, Mark Twain (1881)
Cinderella (story dates back to 800 AD)
At least one Shakespeare play.
(If anyone can help me add to this list, that would be great!)
I've always wondered where this concept came from! How is it possible that you could not recognize someone that you knew who was standing right in front of you? Was there a time when people looked so similar that it was easy to mistake them for one another? How is it that this became to be an exceptable literary element? Anyone who has resources that talk about this, please comment! Thanks. :-)
(Also I think it would be interesting to compile a list of works that involve people leaving this world, having adventures that last seemingly months/years/etc only to return and find out it lasted a moment. So far I have Narnia books and Peter Pan.)