Back in the early 90s, back when I was at school, I had a friend, B, who was into sci fi and fantasy books/TV/Film in a big way. I was a fan of the fantasy genre in books, and we spent many a free period discussing. Around the same time Start Wars: A New Hope was re-released in the cinemas. I went to see it with a friend, and was confused about the episode 4 part. I asked B about this, and she told me that Star Wars was based on a longer series of books, but that George Lucas had decided to start with the middle trilogy, and that the first 3 and last 3 books would be made into films at a later stage. I spent some time looking for the books in second hand book shops but never found them, and generally forgot about them. Years later, when the first 3 films came out, I wasn't surprised.
Anyway, fast forward to last weekend when talking to my mum about the films/books. She got into the whole Star Wars genre quite a lot, and has been to see all the films (whereas I gave up on the whole thing a while ago). I was talking about B and the books and what she told me all those years ago, and my mum said that couldn't be true. According to her, the films came out first, and episode 4 was always the first film, there was never anything prior to it until much more recently, when they did the films and the tie in books.
A look on Wikipedia says that the first books were novelisations of the films, rather than the other way around and the earliest books, outside of the ones covering the first 3 released films, say they were written in 1999 - definitely several years later than the conversations with B.
The nearest to an explanation might be that B meant the books would be written, that maybe she'd read in a fan magazine or something, (internet not being around in those days) but I am sure I remember her saying the books had been written as I'm sure she said she'd read them.
It is also possible she was lying to make herself sound more knowledgeable. Generally in my dealings with her, I never got that impression, and can't think of any other occasions when I knew her to be lying.
I'm also now suffering deja vu because I feel like I've written this before = although searching my messages doesn't bring anything up. So apologies if I have.