One of the things I remember from when Peter Walsh had his TV show--Clean Sweep?--was that for people who had clutter all around, not just a little here and there--clutter to the extent that they could barely walk into the room-- once they cleaned the kitchen or dining room, they could actually use those rooms for their intended purposes. They made meals again, rather than grabbing pizza or chicken on the way home from work, and sat together as a family. If you can't find the pots and pans or get to them because other stuff is in the way, you don't use them. (Well, in my case sometimes it's just cuz I don't like cooking!)
The very basic theory, to me, is that attacking the clutter is one way you are treating yourself better, treating yourself with respect by realizing you don't need to live in disarray. And you're probably treating yourself better in other ways, like how you eat. (And moving boxes, taking them to the dump or wherever could probably burn a calorie here and there.)
(Foilhead: Get rid of the book. You don't need it--you are living it and coming to the conclusions yourself!)