One of the most interesting aspects about Psychology that I will surely remember later on in life is what to ignore. Specifically, the six scientific thinking principles and how we can apply them to our everyday lives. It the most common theme in the book because it appears in every section of every chapter, and I believe it was one of the easiest concepts to understand.
While watching television or perusing through advertisements it is almost comical how often one of these six principles are violated. An obvious example is a tv show about UFO sitings. Somehow, someone compiled enough information to babble on about some UFO they saw for an hours worth of a program and we surely know now by Occam's Razor, that there was much likely a more reasonable explanation for what they saw.
After a semester of Psychology and hundreds of examples of applications of the six scientific thinking principles, finding them in the real world is easy. I suppose that I have created a misleading title. In fact, I now find myself paying more attention to advertisements and obscure eyewitness accounts just for the sake of being able to point out their scientific flaws. This being said, though I pay more attention to them, I certainly discredit them much more often.