Alright, so let's say you're African, and you're living with the possession of your family's business -- a small, but old, printing company. Now when I say small, I mean small. Your family's printing company is so small that all it is in one printer. And when I say old, I mean old. This printer has been in the family ever since, well, ever since there was a family. Let's say about 74 generations for the sake of quantification.
So. Here you are, with your great^72 -grandpappy's printer. Your operation is pretty simple: Every second of every day, your printer prints off one thing and one thing only -- a single sheet of paper containing these words:
The rain in rain falls mainly on the rain
Despite this unwhimsical and altogether unwieldy piece of poetry, you can sell each one of these sheets for one penny, which is just enough to cover the cost of the ink and the paper and put maybe a tenth of a cent in your pocket. Needless to say, you are not exactly getting ahead in the business world.
Now, because this printer has been printing for every second of every day for 74 generations, and every member of this family works from ages 15-55 (forty years) it's done...well, a shitload of printing (about 93,346,560,000 sheets!) And because it prints every second of every day for 74 generations and will continue to do so in the future, it will occasionally make a mistake. About, oh, I don't know, maybe once a day, a smudge will appear on the sheet (which turns out to be an awful lot of mistakes -- over a million of them.) You try to sell them, but your customer's buying habits dictate that they will have nothing to do with your silly little smudges. The smudged sheets make you no pennies and eventually get thrown away.
Then, one day, your printer makes its typical goof and the page ends up looking like this:
The rain in rain falls mainly on the rain.
Whoa. Stop the presses.
Turns out, your printing error has randomly inserted a period into your poetry (I bet you didn't even see it, did you?) And blow me down, people in Africa will actually pay just a little bit more for this new sheet with its shiny new punctuation. So now, instead of making one penny for every sheet sold, you're now making a whooping two pennies for each sheet. Not too shabby for just a dot.
With this newfound profit, you can now afford a second printer. After 74 generations of using only one printer in your business, you now have a second one. This means several things: First and foremost, your cost in producing sheets has doubled. Next, it also means your profits have doubled. And finally, the numbers of errors your printers produce have also doubled.
And this is what life is like for you for a few years, and business is just fine and dandy until one day, when an earthquake happens, and this earthquake is huge. So huge, in fact, that it's downright Cambrian (he said, winking into the camera) and it lasts all day.
Now, because your printers are delicate pieces of machinery, and this earthquake lasted a full 24 hours, your two printers have collectively produced about 172,800 errors. Most of them suck:
The rain in rain falls mainly on the a;odifnapw
Some of these errors though, like your dot of legend, are actually kinda good and include:
The rain in Spain falls mainly on the plain.
The blue rain in rain falls mainly on the rain.
The rain in rain falls mainly on the PLAIN.
So, because you're running a business, you decide to try and sell some of these errors. And, because your customers are of a discerning nature, some prefer a certain kind of error over others, and others prefer a completely different kind of error, and yet some of your errors make zero money at all. The whole thing is good news for you, because some of these errors make you some spinach and you can afford a third printer.
But now the question has come into play of what to print. You decide that because you have three printers and three pretty decent lines, each printer will only print one kind of line. This is about the time you decide to retire and pass the business onto your son (or "daughter" as the more inferior version is often called.) This is where the family biz takes off and things start to get really crazy, so I hope I didn't lose you thus far.
The customers begin to grow very fickle with the sheets you print for them. The "Spain" version of the sheets are extremely popular these days, and those get you about five cents. "Blue" gets one penny, and "PLAIN" is actually losing money by selling for half a penny each. All three printers continue to make errors that make no money. On the whole though, you're slowly making a profit.
Let's skip ahead a few generations. After about 13 generations, your operation is much bigger, with about 100 printers, each one printing off a different line, every second of every day and again, and creating errors along. Some of them read like poetry, some of them sound like a fortune cookie, and some still are simple sentences. Over the course of these 13 generations, one printer managed the word "blind" somehow, and then the word "boys" and eventually one error after a long, long, long line of errors produces this winner:
North Richmond Street, being blind, was a quiet street except at the hour when the Christian Brothers' School set the boys free.
Not too shabby, if I do say so myself (9 out of 10 Irishmen would agree with me). This one line, through nothing but sheer luck (whether it be bad or good) and simply staggering number of errors is immensely popular with your customers. To an outsider, this line is no better than some of the other lines out there, like:
"The marvellous thing is that it's painless," he said. "That's how you know when it starts."
But whatever. The customers like what they like and it's doubtless than the "North Richmond Street" line sells really well. It sells so well, in fact, that you decide to export it. You buy printers in a few places across the world, all of them producing one page per second, one error a day. And the same process begins to occur in those places, but the customers in different places have different tastes. Eventually, after only 73 days, you have different customers purchasing different versions of this popular but same sentence. For instance "South Richmond Street" sells extremely well in Japan, but extremely poorly in Sweden. "North Richmond Avenue" is immensely popular in Brazil, but they use it for toilet paper in India. Needless to say, "South Richmond Street" is sold in Japan, and "North Richmond Avenue" is sold in Brazil.
The sentence itself is in no way superior to the sentences being sold alongside it, nor is it superior or inferior to the sentences sold before it. In fact, stylistically speaking, those shorter sentences about rain falling are just as good. The only difference is that the customer of differing areas will prefer one particular sentence over another.
Every once in a while, a member of this printing family will sit back and go, "Wow, I guess we were really lucky to create a sentence like North Richmond Street." But they're not really lucky. Several generations ago, this particular chain of errors is preferred by the customer, even though it's very, very far removed from the original sentence, making it actually quite faulty. And that's all it is, really, the results of many, many generations of stupid errors that fickle customers liked. In fact, considering the amount of time it took to make this one stupid sentence, the printer family should really be pretty embarrassed.
Actually, some of the customers argue that partly because the sentence isn't very long and not extremely complicated, and mainly because it's so popular, somebody must have wrote it and all its innumerable variants, and all the other sentences and sentences that aren't even around anymore. They would estimate that in happened somewhere within the current owner's lifetime (about two days ago) and didn't take too long (about a half of a second). They also think that the North Richmond Street sentence is vastly superior to all other sentences, just because it's popular. So superior, in fact, that it if you buy it, you can live forever. Some even go so far as to suggest that only one particular type of sentence is good, while the others are worthless (specifically, the one that has the letters A, C, I, H, N, R, S, and T capitalized.)
Some of the customers wonder where the original sentence came from and consider the possibility of an author jotting it down 92 generations ago. Some of the customers see the truly astounding degree of beauty in this all at once unique and mundane sentence and everything it's accomplished and everything it's become in just 73 days, and can easily comprehend a few words about rain happening in 74 generations (about 2,960 years).