What if you dream about writing Hamlet? ;D
Perhaps it is the framing that makes it a work of fiction or the retelling of an experience. Grey area for sure though. I don't think @jayna is just picking on you though and I prefer active community moderators that try to make their community stronger. I am guessing she will reply when she wakes up :)
Well if I dreamt of writing Hamlet it would likely be a lot different from the original, also since Hamlet is in public domain, any reproductions would fall into transformative works. I could see myself making a recording of myself reciting Hamlet verbatim, and no-one could claim it wasn't my own interpretation or the original.
There's one way to argue it wasn't an original, and that would be to claim I am not the same person I was 3 years ago. Although I think it is negligible at best.
Well I'll see what happens next...