Forgetting in order to Remember Better

In human memory, forgetting occur rapidly after the remembering and the rate of forgetting slowed down as time went. This is so-called the Ebbinghaus forgetting curve. There are many explanations of how this curve occur based on the properties of the brains. In this article, we use a simple mathematical model to explain the mechanism of forgetting based on rearrangement inequality and get a general formalism for short-term and long-term memory and use it to fit the Ebbinghaus forgetting curve. We also find out that forgetting is not a flaw, instead it is help to improve the efficiency of remembering when human confront different situations by reducing the interference of information and reducing the number of retrievals. Furthurmove, we find that the interference of informations limits the capacity of human memory, which is the "magic number seven".