We see in every dispensary many cases of abnormal physical suggestibility, people who think that they have caught every disease that they hear about. Among medical students and nurses in training there are always some who become convinced that they have the disease which they have just been studying in the hospital. In the social assistant's work as a taker of histories she must remember that. Highly suggestible people give curiously misleading histories because they become obsessed with the idea that they have some terrible disease. There are three examples of abnormal suggestibility which in my experience recur with especial frequency: _heart disease_, _cancer_, _insanity_. People are amazingly prone to fancy that they have heart disease. If they have any symptoms in that part of the body where they are taught to believe that the heart resides, or if they have heard anybody talk of heart disease, or especially if anybody whom they know has recently died of heart disease, there are many people likely first to believe that they have heart trouble, and then to have actual symptoms which they attribute to heart disease. They often say nothing about this fear. That is just why it is so essential for social workers to dig it out in the course of their history-taking. When people are afraid of a thing they are especially apt to conceal that fear. Insanity is feared, I think, even more often than heart disease. Every doctor is consulted by people who are sure on most trifling evidence that they are going insane. We hear people say, "Why my mind must be failing, for I read down a page and when I get to the bottom I cannot remember what I have read." Or, "I am losing all memory. I met a man recently suddenly and I could not remember his name." These two normal fatigue-products--failure of attention or failure of memory--often make people think that they are going insane. A third result of fatigue which often frightens people is the sense of unreality. Such people say, "I seem to be numb. Things do not seem real to me. I talk to people and I wonder if it is not all a dream. Am I not going crazy?" There have been interesting essays written by French psychologists on the "Sense of the _Déjà Vu_." For a few hours whatever we say or do seems a repetition; we have said, done, heard all that before we fancy. It is a very disquieting sense. But it is usually nothing but fatigue.