Trying to judge the book for what it is, not for what I wish it was. As a brief intro to some very weighty topics (relativity, quantum mechanics, gravity, black holes), it does a great job introducing you to the concepts behind them. It is, of course, impossible to go into any detail on any one of the topics when the entire book is <100 pages... its whole goal is to simply give the layperson a sense of what makes each concept so important. While it left me wanting to read more on each subject, that's more a feature than a bug -- Rovelli's goal is to introduce, not provide complete comprehension.

I learned a few things, and now that I understand some, want to dive in learn more. Which appears to be exactly what Rovelli was shooting for.