During Dr. Russo’s presentation, I understand a few questions about memory. What is memory? Memory is the storage and retrieval of experience-induced changes in the brain. Why do we remember? Remembering is adaptive. It helps us anticipate an uncertain future. For example, in order to avoid poisoning, ancient people remembered how food should be cooked and which plants and animals were poisonous. From one generation to the next, we acquire some common sense and intuition for life. Remember that danger gave people in ancient times a better chance of survival. Is memory always a good thing? The answer is no. Some traumatic memories can make people feel miserable and produce a condition such as PTSD. For example, a soldier who has experienced psychological trauma on the battlefield will respond to certain sounds, such as explosions and gunfire. When they return to a peaceful society and hear similar sounds, such as the sound of fireworks, the pain will be unbearable. They may even make some subconscious moves because of reflexes. Some treatments may be able to cure PTSD, but it is inhumane to let the patient repeatedly recall things that were miserable. Moreover, some surgical treatment methods are not allowed to be used on people. Therefore, most treatment methods are through some psychological therapy.