The participants even accused the experiment of having switched videotapes when they asked to replay the video once more and saw the gorilla. It showed that even the most obvious things could be missed when you are concentrating on something else, also known as the illusion of attention, and the results of the trial allowed readers to realize how their perception of reality is sometimes not what they believe it to be. As the novel progresses, it further delves into other illusions relating to memory, knowledge, and confidence. Chabris and Simons first mention memory and how our simple memories do not last forever. For instance, a traumatic memory, such as the death of a loved one, you will be able to recall much more such as where you where, how old you where, and more. Whereas with a simple memory, such as your first birthday party, is much harder to recall specific details. Another illusion illustrated by the authors in the novel, is the illusion of knowledge. The authors’ conducted a survey where they questioned people in America whether or not they thought they were smarter than the average