Not having a cold for two years is normal and indicates that the body’s immune system is relatively good. A cold is the expression of the body’s immune system responding when external pathogenic microorganisms invade the body. When viruses, bacteria and other pathogenic microorganisms invade the body, the immune system quickly responds and resists the pathogenic microorganisms. If the body’s immune system functions normally, antibodies can be produced within a period of time to destroy pathogenic microorganisms, and the cold can be cured, so the cold is mostly self-limiting. When the symptoms of cold are mild, it is not recommended to intervene with drugs, but the cold can be cured by itself through the response of the immune system. In addition, each time the immune system responds, it produces antibodies against the pathogen to defend against reinfection. If the body’s immunity is reduced, it is easy to cause pathogenic microorganisms to invade and colds often occur. Therefore, two years without a cold is a normal phenomenon, which is a better performance of the body’s immune system. It is recommended to exercise properly in life, such as running, rope skipping, swimming, cycling, etc. Diet should be balanced to ensure sufficient nutrient intake, such as various kinds of meat, eggs, milk and fresh vegetables and fruits. It is also recommended to maintain regular work and rest, avoid staying up late and quit smoking and drinking.