He put forward the famous "forgetting curve", which shows that the process of forgetting is unbalanced, and its trend is first fast and then slow, first more and then less, and the acceleration is negative, so it will not be forgotten to a certain extent. The specific content is: after 20 minutes, 42% forget and 58% remember; 1 hour later, 56% is forgotten and 44% is remembered; 1 day later, 74% was forgotten and 26% was remembered. 1 week later, 77% was forgotten and 23% was remembered. After 1 month, 79% was forgotten and 2 1% was remembered.
Forgetting is a kind of memory loss, which means that the remembered materials can no longer be recognized or recalled incorrectly. Forgetting can be divided into temporary forgetting and permanent forgetting. The former refers to forgetting, and memory can be recovered under appropriate conditions. The latter refers to forgetting, and it is impossible to restore memory without relearning. Forgetting is the opposite of keeping and the condition of consolidating memory.