Not understanding these concepts makes people vulnerable to inflation. Furthermore, even where people do understand inflation, they may lack the negotiating power to respond. If you have a strong union to negotiate on your behalf or if you have scarce skills your employer needs, then you should be able to negotiate a raise big enough to keep up with inflation.
Unfortunately, many South Africans are not in such an advantageous position. Although data limitations preclude an exact measurement of this point, we get some sense of its scale from the Labour Force Dynamics report published by Statistics South Africa. It shows that, between 2010 and 2015, the median wage in South Africa increased by just 6.9%. The median for skilled people increased by 37.8%.