Quasi-pop psychology: The human brain is a remarkable machine. It is fantastic at extracting data from any stream of data it can find. It is aided in this by the neural ability to accommodate and model constant elements of the stream. In the simplest form, you can see this effect with the simple persistence of vision phenomena [1], but the effect can also be applied to fantastically complicated phenomena by our overpowered brains; for instance, can you see your blind spots? (And that's still comparatively simple.) The brain builds a neural net that adapts to the deficiencies of the medium (whatever it may be, movie, audio, etc), streams the data "through" this net, and undoes the medium-induced damage until we are no longer seeing a stuttering 24-fps image, but instead we are seeing John's desparate and heart-tugging last ditch effort to win the affections of Marsha before she finally ties the knot with another guy. And I mean that literally, not merely poetically, the brain is processing the image all the way to its semantic content, which is in some sense the "real" movie.

But the brain, for all its truly amazing capabilities, still has some trivial limitations that any computer would laugh at, and one of them is that the choice of model is not consciously driven, and it can not be changed on a dime. So you go to a 48-fps movie for the first time, and now your brain, sitting in a theatre, smelling the popcorn, watching the corny premovie trivia stuff, flicks in its standard "movie filter", but, alas, oh no, now a 24-fps filter is being fed a 48-fps signal! Now the amplifiers are overamplifying and the net is miscalibrated and what works its way up to the semantic part of the brain is not about John and Marsha but about "Hey! This signal is wrong! The inputs are out of spec! Hey! Hey! The output isn't coming out right! Hey! Hey!" In the audio case, "Hey, after running the automatic sound unwarmers the sound doesn't sound right! Hey!" You "need" the warm distortion of analog audio, you expect it, because you've basically got a hard-coded compensator that won't shut off right away undoing distortion that is no longer present, which is itself a distortion.

The semantic part of the brain, which is still not consciously driven, does not truly understand why it is getting this signal, because it's not like it did anything to create the original net or anything, so it just reports that it is unhappy, and starts casting around for the most likely reason that may be. Not being sufficiently introspective, it decides that rather than its own processing algorithms being miscalibrated for the incoming signal, it decides that the fault must lie in the signal, for which the conscious mind readily provides the seemingly-salient detail that "this is in 48fps", and, bam, explanation achieved. Man Was Not Meant To Know Movies In 48 Frames Per Second. Some people seem to act like this is some sort of Obvious Truth without asking how on Earth such a... specific law could have come to be encoded in our genes, or, yea verily, the laws of the universe itself or something.

Of course, as everyone grows a new neural net to handle the filtering of this new input into semantic content, the lower layers will stop screaming "Hey! Hey!", and the brain, being the magnificent seeker of Information that it is, when it has fully formed 24fps and 48fps nets available to it, will notice that 48fps has a much higher information content, and that it likes it better when given the choice, and indeed may very well decide that 24fps totally sucks.

You will someday stop noticing 48fps. You will someday specifically notice 24 fps and say, wow, how did I ever watch that.

But not today.

If you don't spend much time with 3D, you can observe this effect in yourself usually within the span of one 3D movie. At the beginning, the 3D jumps out at you and you can't help but catch yourself repeatedly "noticing" it. But you'll adjust by the end and not really "notice" it per se; it has faded to the background and you are once again only experiencing the semantic content of the movie. Your neural nets have adjusted. (They're very good at it.) And once you observe the "feeling" of an "unhappy" neural model, you can start noticing it almost any time you're doing something new, new language, new sport, new hobby, almost anything, really.

[1]: http://en.wikipedia.org/wiki/Persistence_of_vision