Understanding and mutual understanding helps people see life prospects, avoid conflict situations, promotes creative, constructive thinking and maintaining health. If a person is committed to mutual understanding with others, he feels confident and happy. Under such conditions, there is friendliness, optimism and humor in human relations. With mutual misunderstanding, difficulties in contact may be associated with differences in character, level of education, intelligence, value priorities, mentality, and national characteristics of people. What is generally accepted in one country may be completely unacceptable in another. This popular science publication covers medical, social and philosophical issues of understanding and mutual understanding.