Re-readings of the last two have never failed to inspire me, but it wasn't until I read her more recent work, Thunder and Lightning, that I felt specifically inspired. Perhaps it's because the other two books are focused on writing practice (which I find helpful but not as essential as Goldberg does), while this one takes writing practice and tells you where to go with it. It could also be because I'm struggling with my current work-in-progress, and any bit of advice is helpful at this point. Still it's always good to be reminded of simple things, such as, be sure to make your characters interesting or no one is ever going to want to finish reading your story; as well as hints on how to do such a thing.
I also thought that reading this book helped me to understand what it means to write what you know, but as I tried to put the idea into words, I became even more confused. However, I do think it has less to do with writing directly from one's own life and experiences, and more with relating what you write to what you know. And no, I'm not going to unpack that sentence--figure it out for yourself.