The first question that many family members face with cancer patients is whether they should tell the patient the truth about their condition. It is very common to conceal the condition from the patient for fear that the patient will not be able to bear it or lose confidence in the treatment. When is it okay to do so and when should it not be done, and how to grasp this degree? Is what the family thinks is good for the patient really good for the patient? And what is really good? All people return to dust, so the life of a person is the life of experience and perception, the knowledge and experience (the perception of the external world) that he or she has acquired. The eternal existence of the objective world is only a tiny part of what an individual can perceive (directly or indirectly), that is, what he perceives as the world. Anything that does not exist for you when you fail to perceive it (directly or indirectly) becomes a component of your world when you perceive it. It is only the role and weight of these components that differ from one time to another, giving rise to your different experiences. Therefore, both the illusory (not directly perceived by touch, sight, hearing, or taste) and the objective (directly perceivable) are real to an individual. In the mind of a farmer who has lived in the fields all his life, perhaps the President of the United States is as illusory (or real) a being as the Jade Emperor. From the time a legal person is able to perceive the outside world (including the unborn), he begins to incorporate the elements that make up his world through his various senses, forming his own world. The earlier one enters, the greater the proportion of elements that have a greater impact on the individual at the time of entry, the greater the proportion of elements that receive repeated reinforcement after entry, and the greater the impact they have on the individual’s experience and behavior. To continue the discussion it is impossible to avoid the question that has been questioned and discussed countless times: what is the purpose of human life? Based on the above understanding, it is not difficult to conclude that the purpose of living is to have the best possible experience. The best experience includes the completeness (breadth and depth), pleasantness, and stability of the experience (not to be discussed too deeply here). If the condition is concealed because of the fear of adverse effects on the patient, a deeper reason is that the aggravation of the patient’s condition will lead to an unpleasant experience for the family, and the condition is concealed to avoid this unpleasant experience. However, people influence each other, and in society they are generally constituted in small groups (family, class, group, etc.), with family being the most important and common. The influence of the individuals within the group is very significant. Therefore, it is not scientific to consider an individual’s experience alone. The evaluation should be based on the best overall experience of the members of a small group. The size of the group is usually the size of an average family (2-5 people, which is generally the number of people one can get closest to in social interaction), and because of the small size, the influence of each individual is very significant. Therefore to address the beginning of the problem it is important to first understand what kind of group the patient is in, what kind of person the patient is, and what kind of person the family is.