Hamming invented a lot of cool stuff, but he is best known for sitting down and asking people why they weren't working on the most important problems in their domain. Presumably he didn't make a lot of friends with this strategy, but his is the name we remember, not theirs.
This book is excellent excellent excellent. The thesis is that a life lived without producing excellent work isn't one worth living. Hamming describes the book as a manual of style; while university is good at teaching technical skills, it's not very good at teaching the important stuff that falls /between/ the discrete subjects. Like how to choose important problems to work on, or where insight comes from, or how to stay ahead of the trend and not become obsolete.
To this extent, Hamming talks about his own successes and failures (though mostly his successes --- he says it's more important to study success than failure, since you'd like to replicate only the former.) He's obviously proud of his accomplishments, which is a refreshing note from most technical autobiographies, in which the authors present a cool, modest description of their work. Hamming provides commentary behind each of his wins, describing the circumstances that lead to it, and how having a "prepared mind" helped him jump on it before others did. He further notes how he could have done better, and gives explicit advice to the reader for how to do a better job than he did.
This is a wonderfully insightful book, and is chocked full inspiration and interesting technical topics. If you're in a technical field and you'd like to do great work, this is mandatory reading.