Initially after surveying this book, all that registered with me was the complex mathematics.  Even the first couple pages, which preview the whole book, seemed beyond my grasp.  But as I pushed on it got easier and easier to comprehend.  It lays out concepts in an exceptionally organized way.  I didn't believe is was a Physics primer till after I finished the first chapter.  Now I truly feel that it is a primer.  But it does take some Calculus and Linear algebra to understand the math.