Most fans who were following the story in 2001 were familiar with The Legend of Mata Nui, as the Turaga told it to the Matoran of Metru Nui who had emigrated to Mata Nui by that time. As a quick refresher, it goes somewhat like this:
"In the time before time, the great spirit Mata Nui descended from the skies like a burning star, bringing we, the Matoran to this island, and gifting us with the three virtues: unity, duty, and destiny. We named this island after the great spirit himself in his honor, and it was a paradise for some time. But, Mata Nui had a brother; the dark spirit Makuta. Makuta had followed his brother to our paradise, and he was jealous of all the praise that he received from the Matoran. So, Makuta cast Mata Nui into a deep, dark sleep...
There might have been a segment predicting the arrival of the Toa Mata, but it doesn't matter much to my point, as the types of words and the heavy use of simplistic metaphors is present in that section too. The legend is known for being very simplistic, greatly condensing and metaphorically describing much of what we actually know to have happened in the canon during the months preceding, during, and immediately after the Great Cataclysm.
If a person were to lose all every single one of their memories, than they'd practically be an animal, with little to no human intelligence. This is regularly done on purpose to many of the droids in the Star Wars universe, and not only do they lose their memories of past events that they witnessed or learned of, they lose their abilities to read, write, talk, and assemble or disassemble even simple mechanical objects; in short, they need to be re-taught everything. If the Matoran of Metru Nui really lost every single one of their memories, than they would have very little intelligence for several months, or possibly years of their time on Mata Nui; it would depend on how long it took the Turaga to reteach every individual Matoran everything, or for the Matoran to teach themselves. During the period in between being liberated from the pods in which they were "sleeping" and having completely mastered everything that they needed to relearn, the Legend of Mata Nui story would have been useful in explaining their predicament in simple terms: basically, that there's a guy named Makuta, he's evil, and he hates you, much like a parent would do for a very young child. The Legend of Mata Nui was crafted to be very simple because Matoran with complete memory loss wouldn't be able to understand a more complex version.
This could also explain why the majority of the technology on Mata Nui was many times more primitive than that of Metru Nui prior to the Great Catacylsm; the Matoran would have had to start from the most basic tools and work their way up in terms of developing new technology, which was probably further stunted when Teridax's rahi attacks began in full force. We don't know how long it took the Matoran to invent their chute system after they had begun to live in Metru Nui, but it easily could have been tens of thousands or even hundreds of thousands of years; human civilization has been around for roughly 11,000 years, and we haven't invented a chute system for transportation just yet.
Edited by Artakha's Nephew, May 29 2014 - 07:25 PM.