I'm not ashamed to say that I own that book. I have read it. My SO has read it. Actually, my SO was the one who purchased it and read it first.

When my SO is sad or mad or whatever emotion he feels beside happy he becomes quiet. He is a very introverted person. In our case he has an actual "cave" he retreats to. When we bought our house I wanted to make sure he had somewhere he could go when feeling this way so we made him his own room/office. I still forget that this happens, though. The whole thinking everyone hates me the second they make eye contact thing. He has explained to me that when he retreats to his "cave" and I pester him...and pester him...and pester him....it's because he doesn't know what's upsetting him. He usually has no idea why he is feeling the way he is feeling. Or he doesn't realize how it's affecting him. That helps me understand.

Just to point out, I'm making him re-read the book. It really helped us understand eachother better but I think we have gotten away from it. Maybe have your SO read it. It's very hard for men to understand how emotional us women can be just as it is hard for us to understand how men can be so personal.