The world is real, but human knowledge and understanding of the world are subjective and limited. Human beings understand the world through their senses and rational thinking, but human senses and rational thinking have certain limitations, which make human beings' knowledge and understanding of the world have errors and misunderstandings. First of all, the human senses are limited. Human beings can only perceive the world through their five senses, but different senses perceive the world differently, and each sense has its own limitations and blind spots. For example, human vision can only perceive visible light bands, while light in other bands cannot perceive; Human hearing can only perceive sounds in a certain frequency range, while sounds at other frequencies cannot be perceived. Therefore, there are limitations in human perception of the world, and it is impossible to understand the world comprehensively. Second, there are limitations to the rational thinking of human beings. Human beings analyze and understand the world through rational thinking, but rational thinking itself has errors and limitations. For example, the human mind is susceptible to factors such as experience, beliefs, culture, etc., which can affect the knowledge and understanding of the world. In addition, human rational thinking is also prone to subjectivity and one-sidedness, which makes the knowledge and understanding of the world biased and misunderstood. Therefore, there are subjective and limited human knowledge and understanding of the world, which makes human knowledge and understanding of the world have errors and misunderstandings. In order to know and understand the world more comprehensively, we need to constantly explore and discover, overcome the limitations and errors of the senses and rational thinking, and gradually approach the truth and truth. At the same time, we also need to maintain an attitude of humility and awe, respect nature and life, and live in harmony with the world.