Somewhere in the bottom hemisphere, among koalas and wombats, a guy once thought: “this civilization sucks”. But instead of whining on the internet, he went into a forest, methodologically and silently building everything from scratch (i.e., without modern tools) out of mud and sticks. And videotaping it.
Or maybe he liked the civilization so much that he wanted to learn how to rebuild it if something will go wrong. Or to role-play like those Amish people do, or as a religious thing, as Tolkien fans practice. Or to explore living independently from society, as Ted Kaczynski tried before exploring living in a prison. As a hobby or as a way to make some money, as an art project, as a bet, to show off, or whatever: there is a lot of perfectly valid reasons to go alone into a forest and start building everything out of mud, but we don’t know which one it was, because he doesn’t blabber in the videos. Okay, actually he writes that it’s a hobby, but could have been about anything.
It’s not just some dull stuff like stone tools, huts, and dress (though that too), but he also harnesses the fire, making pots, charcoal, chimneys, kilns, furnaces. No metal (not even copper) tools yet, but there is a bit of smelting experimentation, so he’s somewhere at Neolithic Era level of development (see timeline of historic inventions for an outline). It’s probably a long way from that to fancy stuff like any usable electronics, radio, and computers, even with the modern knowledge (but without modern physical tools or prepared materials), but the guy is fairly young, and probably has enough time for that ahead of him.
The videos are quite impressive and interesting to watch, and probably it’s fun to work on: even though sometimes it takes hours to make a single hole in a log, it still looks more fun than to waste hours/days/months/years doing nothing in particular. And then he gets a log with a hole in it!
As was mentioned, the guy is silent in the videos (what makes them similar to creepy videos where other silent people do other weird stuff; anonymously until recently, too, as wikipedia says), but there are subtitles that explain what’s going on, what are the immediate goals of his actions. They are pretty informative, so don’t forget to run youtube-dl with the --write-sub option in order to grab subtitles along with the videos. The blog contains additional information on the projects.