I recently viewed the movie Inception and enjoyed it much. With out reveling too much of the plot it involves the uncertainty of reality as it relates to dreams. The plot is intricate and well written and I was surprised at how many of my contacts enjoyed it. It required some concentration to follow and understand the plot. Some thing that I was pleasantly surprised to hear. I was also surprise at how many folks thought the idea was new one. The uncertainty of reality with respect to dreams and other venues has a history.
From our recent history the movies Matrix and The Thirteenth Floor were to computers as Inception was to dreams. I found both enjoyable and worth viewing. TV has also featured this concept. One of my favorite episodes of The Twilight Zone (TZ) is Perchance to Dream besides being the first TZ show written by Charles Beaumont (a favorite writer of mine) it featured a dream sequence that caused one to question reality. It can viewed at Youtube.
The print media has also explored the idea. Perhaps one of the more famous examples is An Occurrence at Owl Creek Bridge by Ambrose Bierce (Another great writer of speculative fiction). It was also featured as a very rarely seen episode of The TZ and can also be viewed at YouTube.
My very first exposure to this idea though was in an old Science Fiction Novel by Laurence Manning titled The Man Who Awoke. In this story civilization sleeps their life away in dreams of their design. Does this sound familiar…ala The Matrix.