[ WP ] Recently a new tribe was discovered in a rainforest that has never been seen before . Rather than being behind the rest of the world technologically , they are far more advanced .

30 Years ago, I had left the tribe I was now about to see again. 
 
 Isolated in the depths of the jungle, which was becoming smaller every week, they were unique in many ways. They valued intelligence more than strength and had their own little strategy game - a mixture of go and mancala. Their heroes were the ones who could get lots of food for the tribe while barely lifting a finger. 
 
 They did not value technology much - only had a shrug when I showed them a knife, explained guns to them, or such. But when I taught a few of them how to read and write, they got much more interested - though mostly in things concerning biology, chemistry, and such. 
 
 They were really clever - quickly managed to produce their own soap after reading about it in one of the books I brought along with me. And after the first such successes, everyone wanted to learn to read, and everyone tried out everything in the books, often with funny, and sometimes with scary results. But they quickly learned to be careful when things became dangerous. 
 
 I left the tribe once every week or so, and brought more and more books - all areas of science, at first simple books like encyclopedias and school books, in the end the most prestigious affordable scientific literature. 
 
 When I went back home, I made sure they'd get the most important published papers - in full detail, as I knew they were already past the pop-stuff. 
 
 For a few years, I received a letter every once in a while from one of the kids I taught how to read and write, with funny stories of their newest exploits. Later, when she married, the letters became less, and more about herself, her feelings, and her relations. She mentioned how grateful everyone was for the books and journals. Not much more. 
 
 Now that I was a pensioner, I wanted to see what had become of them. So I traveled to them. 
 
 I was greeted with a lot of laughter and friendliness. There were some comments how much I had changed, which sounded strange, but I could n't really sort them in. 
 
 The kids I had taught how to read and write were now grown ups - but looked more like 20-somethings than the around 40 year olds they should be. 
 
 There were a lot of others I did n't recognise at first - all of them looked as if they were 20-somethings, except the kids and youth. 
 
 They still despised technology to some degree - living in simple but now very big huts. They also showed me the labs each of them had. Some of them in tents inside their huts, apparently to keep them clean. 
 
 I did n't know what they did in those labs - they were not fooling around and showing off like they did when I left. Nor was it a big thing for them to talk about. 
 
 Only when I recognised one of the strangers did it occur to me: the woman, a mother of two of the children I taught, and who I had liked a lot back then, had not changed the slightest bit. I looked her up on my computer, where I had stored digitised copies of the photos I had made back then. I showed her the picture. I asked her whether it was her mother, not wanting to believe what I saw with my own eyes. Until I realised it was undeniably the same person. 
 
 Relationships were in flux in this tribe. And so she stayed with me. But when I wanted to kiss her on the evening of the second day, she held me back. She led me to a section in a large tent in one of the larger huts which looked like an operating room. She asked me to lie down. They gave me something which made me fall asleep. 
 
 The next day, when I woke up, I felt really good - full of energy, like after a really good night's rest when I was 20 years younger. I could n't see much of a difference in my body, except that my skin seemed to be a little tighter, and some scratches and other blemishes had gotten less. 
 
 I asked what had happened, and they were astonished that I was unaware. Did n't I send them all the books with all the knowledge which they applied? 
 
 Over the next few days, my skin got elastic again, my eyesight and hearing went back to what they were in earlier times, and even my brain felt quicker. 
 
 And then the shocking parts began: I could hear distant people talk when I paid attention, feeling my ears move a little to focus the sound into my hearing channel. I could make out leafs on trees in distant mountains when the weather was clear. I somehow knew which direction was north at any time. And when a fog came, I knew exactly which direction the sun was - because I could see the polarisation of the light. 
 
 Every day, I discovered new abilities within me. It was like finding out how to move a muscle you never knew you could control. Or like seeing color for the first time. 
 
 A small black dot formed on my forehead - I had barely noticed it on the darker skin of the tribe. And thought it was an ornamentation. But it enabled me to see longer electromagnetic waves - turning the milky way into a bright spectacle, making the far away cities look like fountains of light when watching them from a mountain, and making my phone glow with every call I made when I was near a cell tower - the closest of which was a day's journey from the tribe. It also gave all the humans a little glow from their heat. 
 
 Then, when my body looked barely 30 years old, the skin modifications which I had seen on the tribespeople, stripes on the chest, appeared on my body, too. Everyone was happy seeing them, while I was puzzled what they would be good for. Eventually, some kids of the tribe led me to a nearby lake. They told me to dive, some of them leading the way. When I was under water, I realised I could hold my breath longer than expected. And when the oxygen level went down enough that I thought I should get up again, the stripes on my chest opened up and started filtering water! I could move my lungs, and felt that I had something like a water sack between the lungs and the ribs, filtering oxygen out of the water. 
 
 Then one of them spoke. While under water. His speaking sounded different, but was understandable. It was n't caused by air moving out of the lungs, but by a new muscle close to the voice cords, which would vibrate against the water like a speaker against the air. And I could do it, too! - after some trying. 
 
 They had houses in the lake. Their tribe was at least twice as big as I thought. The lake also had a very deep cave, which apparently was a mine providing a few useful minerals. An underwater river connected the cave to another lake further up a nearby group of hills - which was also the reason why there was always enough oxygen in the lake. A feat of brilliant natural re-engineering, as I was told right then. 
 
 I thought about what would happen if anyone found out about all their achievements...
