I read a book in middle school that I've been looking for, for years. If I was to guess, I'd say maybe 60s-70s. I'm 34 now, so middle school would have been 1996-98.
I can't remember much of the story, but it's about a teen boy and girl running from people who wanted to put them in working fields or a labor camp, maybe. It's set in a dystopian future, I think. While in the working fields, the people are in a dream state, where they believe they are happy, but in reality they are forced to work.
At the end of the book
they ultimately escape, but the twist is that they are dreaming and were in the working fields (or maybe just the boy was?).