"The discovery of fire, or, more precisely, the controlled use of fire was, of necessity, one of the earliest of human discoveries," according to About Archaeology. "... The human control of fire likely required a cognitive ability to conceptualize the idea of fire, which itself has been recognized in chimpanzees; great apes have been known to prefer cooked foods, so the very great age of the earliest human fire experimentation should not come as a terrific surprise."
Comment: "Conceptualizing the idea of fire" is one thing, but learning how to make it is another. While I was watching this video about firesticks, I had to wonder how this method of creating fire was ever discovered in the first place. After all, prehistoric men couldn't have known that friction would cause heat which would in turn ignite kindling. This isn't intuitively obvious and it doesn't seem like the kind of thing you could just stumble across by accident. It takes time to make fire this way and the method requires specific materials and techniques.
I can see how a Stone Age hunter might accidentally learn that striking stones together creates sparks which in turn can start a fire. Sparks are a natural byproduct of flintknapping, but I don't see how anybody could inadvertently start a fire with friction. It takes too long, for one thing. The more I think about how the basic principle of this technology could have been discovered, the more mysterious it becomes.
"Successfully creating fire by friction involves skill, fitness, knowledge, and acceptable environmental conditions. Some techniques involve crafting a system of interlocking pieces that give the practitioner an improved mechanical advantage; these techniques require more skill and knowledge but less fitness, and work in less ideal conditions." Source: Wikipedia.
The discovery of how to use friction to create fire becomes even more baffling when you realize that it must've been done millions of years ago, perhaps before modern humans even came along:
"The controlled use of fire was likely an invention of our ancestor Homo erectus, during the Early Stone Age (or Lower Paleolithic). The earliest evidence for fire associated with humans comes from Oldowan hominid sites in the Lake Turkana region of Kenya. The site of Koobi Fora (... dated 1.6 million years ago) contained oxidized patches of earth to a depth of several centimeters, which some scholars interpret as evidence for fire control. At 1.4 million years of age, the Australopithecine site of Chesowanja in central Kenya also contained burned clay clasts in small areas." (About Archaeology)
The idea that Australopithecus knew how to make fire is truly mind-boggling.