Daydreaming, of course, is only part of the story.
Although it's easy to think that "paying full attention" is synonymous with forcing our brains to suck up every bit of important sensory data that they can without distraction, such a thing actually appears to be impossible.
Each blink interrupts the flow of data into our eyes, but our brain helpfully fills in the gaps.
The retina's famous blind spot also limits the amount of visual information our eyes take in, but once again the brain helpfully fills in the gaps, creating the illusion that these blind spots don't exist.
I once read that our brains do much the same thing when we're listening to another person speak, automatically editing out the irrelevant pauses and ummms and automatically smoothing over the slurs and missed syllables and accents. (According to E. Bruce Goldstein's textbook, Sense and Perception, "The sloppy pronunciation of most words in conversational speech makes about half of the words unintelligible when taken from their fluent speech context and presented alone." Only about 60% of normal sentences are perceived correctly when moderately high background noise is present.) What we end up remembering is the meaning of the conversation (as derived by our brains from an imperfect source) rather than a verbatim transcript of what was actually said. Depending on who we are (and other circumstances), that derived meaning may have very little to do with the intended meaning.
Which brings to mind this passage from James L. Christian's textbook, Philosophy: An Introduction to the Art of Wondering:
Bertrand Russell once wrote that the stupid person always reduces brilliant concepts to his own level of stupidity since he must oversimplify them to understand them. Something like this takes place in our communicating with one another. Because of our own pre-established conceptual points of view, we "translate" what another is saying into the familiar experiences of our own world. In doing this, we miss the living experience which the other person is in fact attempting to convey.
Is the situation better or worse here than it is with the eye - a sense organ that, according to Christian, delivers photons and waves to a brain that interprets them as colors that exist only in our heads?
Flash a green light for better, a red light for worse.
Issues like these gave spice to my long-ago college life before settling down and going to sleep beneath the steadily falling detritus of humdrum everyday life.
They were reawakened this morning when I myself woke up yet again with a ringing in my ears.
It's not particularly unpleasant or bothersome, but it *does* seem as real as any dial tone.
Except, of course, it isn't. It's merely tinnitus - an inner-created sound that my brain often insists is coming from without.
Wikipedia explains the situation this way:
Tinnitus... is the perception of sound within the human ear in the absence of corresponding external sound.
Tinnitus is not a disease, but a symptom resulting from a range of underlying causes that can include: ear infections, foreign objects or wax in the ear, nose allergies that prevent (or induce) fluid drain, and wax build-up. Withdrawal from a benzodiazepine addiction may cause Tinnitus as well.
Tinnitus can also be caused by natural hearing impairment (as in aging), as a side effect of some medications, and as a side effect of genetic (congenital) hearing loss. However, the most common cause for tinnitus is noise-induced hearing loss.
As tinnitus is usually a subjective phenomenon, it is difficult to measure using objective tests, such as by comparison with noise of known frequency and intensity, as in an audiometric test. The condition is often rated clinically on a simple scale from "slight" to "catastrophic" according to the practical difficulties it imposes, such as interference with sleep, quiet activities, and normal daily activities.
Tinnitus is common. About one in five people between 55 and 65 years old report tinnitus symptoms on a general health questionnaire and 11.8% on more detailed tinnitus-specific questionnaires.
Even though one part of my brain understands what's going on here, another part refuses to believe it. That part insists that what I'm hearing really is "out there" and not just some self-generated whine.
As it happens, I came across a segment on "Unsolved Mysteries" the other evening while randomly flipping through my cable channels that focused on this very issue. Apparently there was this man in New York City who began hearing a dull, grinding rumble that he was sure was coming from Out There. He spent a lot of time trying to track it down, thinking that the source must be a highway, or a rooftop air conditioning unit, or some such thing. No luck. The sound continued even when he went deep into a cave....
At this point it might seem obvious that he, too, was a victim of tinnitus. But his ear exam (unlike mine) revealed nothing wrong.
And then reports started coming in of thousands of other people claiming to hear much the same thing.
One of these people was a radio sound engineer who managed to re-create the sound for others using various tapes and what-nots. When other "victims" of this maddening sound heard his re-creation, they seem to have immediately said "Yep! That's it! More or less...."
One hypothesis was that these people were especially sensitive to the US Navy's ELF program - a high-tech means the Navy had developed to stay in touch with its submarine fleet all around the globe. When the program's transmitters were shutdown in 2004, one man said that he did indeed experience some - but not complete - relief. For many others, however, the noise they heard droned on.
Or show the program claimed (without much detail or supporting evidence)....
The ability to readily determine what's us and what's not, what's inside us and what's outside, what's objective reality and what's subjective delusion would seem to be a pretty important one.
Unlike some people I could mention, I think I (and most of my humanist and atheist friends) do a pretty good job telling the difference between our daydreams and our fantasies and the nature of the universe.
But now, suddenly, at what's perhaps the more basic level of sense data, I find myself unable to completely trust myself.
Hearing *isn't* believing.
So what is?
Well, the conceptual framework inside my head that's interpreting things, I suppose. It's a framework that includes knowledge of neurons, and nerves, and the impact a long-dormant but now suddenly restless virus might have on a highly sensitive inner ear. My doctors have explained it all so well. I can find fine medical illustrations online that back up what they say to an amazing degree.
Yet still part of my brain insists the strange humming sound I hear when I wake up in the morning really and truly is "out there"....
Is it any wonder that earlier humans, raised exclusively on the mythical conceptual framework of spirits and other worlds, seem to have accepted what this part of the brain was saying?
Is it any wonder that they seem to have often understood inner voices and dreams and hallucinations as communications from the Great Beyond and almost never as self-generated noise and distortion?
No, of course not. As Russell more or less said, we dumb things down until they're on the same level as our ignorance.
The real wonder is that even in an age of science and widespread literacy, so many people feel the need to dumb things down to a level of ignorance scarcely indistinguishable from that of ancient shamans.