The history of braaing, the origin of fire and the controlled use of fire are all pretty connected, not only to each other, but also to South Africa. Scientifically speaking South Africans are not only the best braaiers in the world, but braaing also originated here.
The theory is that the first braais happened when meat was accidentally dropped into fires, later removed and then eaten. The early humans found that the meat not only tasted better than raw meat, but could also be chewed easier. The rest is history, as they started dropping meat on and into fires on a regular basis. An additional advantage of their control of fire was that they were now able to ward off predators. The early humans also crafted stone tools like axes and cleavers. Their control of fire together with the tools also meant that they could leave Africa and travel into the colder northern hemisphere.
The scientists proved that the early humans who were living in the area were responsible for controlling the fire. The sharp reader will think that the fires were not necessarily controlled, as they could be bush fires started by lightning. But Dr Brain tested the charred remains of the bones that were excavated and found that the ferocity of the burn that created the charred remains were much higher than any heat produced by bush fires, it had to have been a fire that was fed with wood repeatedly.
Considering that the origin of braai is in South Africa, very fitting then I think you will agree, that South Africa has a National Braai Day.