One of my favorite pleasures in life, as I've mentioned before, is what I call "The Rush." The jump of realization and epiphany that comes when you suddenly understand something that was previously kept hidden from you. When I experience it, I tend to give off a little laugh at the sheer, wonderful cleverness of it all.
(The Rush is what Q is talking about, I think, as the reason he spares humanity in the Star Trek: The Next Generation finale, "All Good Things...", the moment when Picard saves humanity, not through technology or bravery or even the power of friendship and loyalty (although his plan does require all those things), but in the moment at which his mind expanded to understand the bizarre nature of the problem. It's that quality, Q says, that marks a species for greatness, and I've always had a soft spot for that idea.)
There are plenty of opportunities to find the Rush, at varying degrees of difficulty. Whole genres of video gaming are built around encouraging players to epiphany. But prior to the invention of gaming, people looking to simulate the feeling (that is, those who don't get it naturally in jobs that rely on problem solving capabilities) were probably best served by reading mystery stories.
"Do you promise that your detectives shall well and truly detect the crimes presented to them using those wits which it may please you to bestow upon them and not placing reliance on nor making use of Divine Revelation, Feminine Intuition, Mumbo Jumbo, Jiggery-Pokery, Coincidence, or Act of God?"
-Oath of the Detection Club
If you've read mystery stories with any regularity, you've encountered one that relies on at least one of the things damned in that lovely oath. Is there anything more upsetting than to have a never-mentioned clue appear out of nowhere to let the quirky detective suddenly lay a solution in front of the readers?
For me, and, I imagine, many others, the mystery story is a kind of game (ignoring the books, usually written for children, which make this explicit by presenting each chapter as a case and asking the reader to try to solve it), a race between the reader and the fictional detective to see who can solve the murder or robbery or what have you first. The detective has the advantage that, being a fictional creation, sprung from the forehead of the author, his eventual victory is inevitable. Barring some twist or narrative trick, the mystery WILL be solved by book's end.
The reader, on the other hand, has the advantage of being directly exposed to the text (or camera, in a filmed mystery). This limits the number of things the reader has to focus on to the bare minimum of what the author is willing to describe (or the director willing to show). At the same time, the reader/watcher also has the knowledge of all the literary conventions or editing tricks that a given genre has given rise to - foreshadowing, long lingering shots of significant objects or characters, all the tricks writers and directors use to imply significance that are invisible to the characters within the story.
(An example of an inversion here - I recently saw the excellent Source Code, and infuriated my mother by calmly pointing out the film's mystery villain within minutes of the film's start. I was able to identify him not because he was focused on, but because he seemed, very intentionally, to be OUT of focus... An act of misdirection that primed me to suspect him, and which I was only able to recognize through knowledge of the meta-information of editing/shot composition.)
Authors/directors can, of course, use those same tricks to mislead, subvert, confuse, or outright lie to the viewer - but that's all part of the fun. One of the joys of Andrew Hussie's amazing Homestuck (available at www.mspaintadventures.com) is the way it uses foreshadowing, established narrative structures, and pacing to play elaborate games with reader expectations.
Part of the fun of a story is its unpredictability, and this one has had plenty of it so far I think. Unpredictability is a significant basis for suspense, and I'm sure has other benefits we could examine. But I think there is also enjoyment value in occasional predictability, or rather, guessability. Setting up some obvious clues, and running with them to their logical conclusion. It's like throwing the reader a bone, particularly those who may be prone to feeling a little overwhelmed by getting perpetually outfoxed by the narrative.There are pages and pages of speculation on Hussie's stories on his forums, and while some of it is asinine stuff and mindless guesses, a vast amount of it is strongly informed by the reader's understanding of how stories work generally, and how Homestuck - which is based on multiple viewpoints, subversions of dramatic moments, sudden bursts of epic action that significantly alter not only the content but also the tone and genre of the story, and a thousand other strange and wonderful elements - works in the specific. Weight in these arguments (which have a pretty good batting average of coming out true) is often given to considerations like the amount of time the text has spent with a given character, obscure bits of foreshadowing spread over the course of hundreds and hundreds of pages of story, and the nature of reader expectation itself. Each of the speculators is a detective, sifting through the text of the comic to solve the mystery: What happens next?
Of course, Homestuck isn't really a mystery story at all. But that's kind of the point: Every story is a mystery story, if you're willing to think about it. Every story can be a race between the reader and the director to work out how it's all going to end, what the next pages hold. The Rush from working out where a plot is heading, through clues both textual and subtextual, is as strong as the one produced by any product of LucasArts or Sierra.
Plus, the level of thought required to accurately predict what happens next forces the reader/watcher to actively engage with the work. Anything worth reading, I think, is worth thinking about. Obviously, there are shows or books that we treat as popcorn, that allow the reader/watcher to "shut their brain off" and just experience. But really appreciating something for the merits its creator was trying to express, to give it the full benefit of the doubt and assume that it was made by people who were thinking and caring about what they were producing (dangerous, because when you're wrong, a work can be ruined for you - see my entire relationship with the TV show Heroes) requires having your brain on - a process I've always found exhilarating.