Linear Algebra is well worth the trouble to read about.

When I was a teen, I bought a fancy new calculator, an HP 15C, that featured matrix operations. I borrowed a book on Linear Algebra in order to learn how to use it effectively. (If I knew how much they would sell for as antiques, I would not have thrown mine out!)

I recall calculating a "cash discount" table at a gas station (I worked as a cashier part time) using a single operation to populate the matrix giving the table. It's basically the kind of stuff you do in APL.

Later when I took L.A. in college I had an easy time. It's really the simplest "advanced" math there is. It's more like programming.