This book was quite interesting and made me wish I could attend the USMC school for which this book was written about.
In the book I learned several things, and terminology for conceptual ideas that I had wondered on, but didn't have explicit direction. Such as "proximics, Iconography, Atmospherics", etc.
What I find a lot of times with books like this is that it helps streamline and compartmentalize my thoughts and focuses them into categories instead of loose ideas. I think on an instinctual level, and the book even suggests this, we know when things are wrong- but we elect to ignore our senses. This book helps to dispel that notion to make you more aware so that you can be "left of bang"
I do think that after reading this book, I look at the world a little differently. It took what I would consider a decent sense of situational awareness, and fine tuned it to be better able to assess what I was observing.
Have you noticed any changes in your situational awareness since reading the book?