I've been programming for decades and quantum computing was always a topic of interest. I've read about it but always felt like I was missing something. This book finally gave me the foundation I needed. It provides that "one level down" insight needed to grok the higher subject. The author makes no assumptions about your existing math skills (so-so in my case). Instead, he starts with the basics and works you up from there. Suddenly you are reading about (and understanding) linear functionals and eigenvalues. An all-around great read for anyone in the space or interested in learning more.