It still applies even if you don't know what matrices are. One kind of programmer will look up what it is and how the algorithm to invert it works, then implem

It still applies even if you don't know what matrices are. One kind of programmer will look up what it is and how the algorithm to invert it works, then implement that. The other kind of programmer will search for libraries implementing these features. The end result is that the first kind of programmer will know how a lot of things work, while the second kind of programmer will know a lot of libraries.