I'm not even self-taught, it's just that when I was studying (CS degree, like 15 years ago) we did have a mandatory linear algebra course, graph theory course, statistics course etc., but we never * actually * used any of that in practice, it was all algo this, big o that, data structures, design patterns, languages, compilers, SQL etc. Now that I'm thinking about it pretty much the only course we had to use some linear algebra in was the 3d rendering one. ...

And then you work on .net/java/sql/server crap for a decade and you forget even the little math you used to know :D