I very much second this book. I'm not sure it teaches anything groundbreaking/new, but just seeing the words on a page was hugely valuable to me in the same sort of way that saying the things that rattle around in your head out loud to a therapist is. It really helped me gain some clarity on my own direction.
It is ostensibly a book about time management; it's in the subtitle. It seems actually to be a book that says: We can't get it all done. We're still good enough. Get clear on what's important and spend time on those things