I'll never really get to grips with quantum mechanics, but this book gave me a clearer outline than I had before. It sketches out the development of theories of matter over, roughly, the last 100 years. There are plenty of anecdotes and context notes to make this a comfortable read. But having read it, I wanted to read the science bits again, without the human interest. Perhaps I should have used a highlighter, but I hate them. I could have done with more explanation in places. For example, I'm sure it's very difficult to explain why continuous symmetry with respect to time leads to conservation of energy, but devoting just a sentence to it doesn't seem to be seriously trying. Anyway, I learned quite a lot. Not least, what the Higgs mechanism is, and why the small fraction of mass it explains is so important.