Again, I’m not saying that one’s thoughts about reality are all that matter. I would be the first to admit that it is generally a good idea to keep rats out of one’s bed. But it can be liberating to see how thoughts pull the levers of emotion—and how negative emotions in turn set the stage for patterns of thinking that keep them active and coloring one’s mind. Seeing this process clearly can mean the difference between being angry, depressed, or fearful for a few moments and being so for days, weeks, and months on end.