The mystery of memory

  How big is the hard disk of the brain’s memory capacity?
  In March 2014, an article in Nature magazine analyzed that the structure of 13 neurons in the mouse brain used up to 1TB of data. And an adult brain weighing about 1.4 kilograms has about 100 billion neurons. But are 100 billion neurons all used for storage? In fact, not all of these 100 billion neurons are used for storage in the human brain. Even a great scientist such as Einstein only uses one-third of his brain’s functions. More cells in the brain are in a state of “unemployed”, and human beings have not fully utilized all cells. Let’s calculate the data size of the human brain storage capacity. Even if one-tenth of 100 billion neurons is used, as many as 10 billion neurons are in use. And the 13 neuron systems of mice use 1TB of data, so the storage capacity of the human brain is equivalent to 760 million TB of data. Even if the current hard drives up to 8TB are used to store these data, nearly 100 million hard drives are needed. If you stack these hard drives (each with a thickness of 41 mm), it is about 3,895,000 meters, which is equivalent to the height of 4,703 Burj Khalifa (828.14 meters), the tallest in the world.
  Where are the memories before 3 years old?
  Why do we have a hard time remembering things before the age of 3? Where are the first memories of our lives?
  When did childhood memories begin to blur until they are forgotten forever? A study on childhood memories found that early memories are often lost from the age of 7. Although many 3-year-old children can remember what happened the previous year, these memories can only last until the age of five or six. In the year of 7 years old, childhood memories declined rapidly. By the age of eight or nine, most children can only recall 35% of their childhood life. Psychologists believe that this is because at the age of 7, the way people form memories begins to change. Before that, children lacked the concept of time and place, and the form of their memories was immature; while in older children, The content and form of recalling early memories tend to be adults.
  Why can old people remember things from childhood, but not what happened recently?
  The elderly have a bad memory of what is in front of them, but they remember many things from their childhood, even trivial ones. so, what happened? When people are young, they can have the conditions to concentrate more on learning. Conditioning is easy to build and consolidate, so children and young people have particularly good memory. As the age increases, although the comprehension ability increases, the conditioned reflexes established are sometimes not consolidated, so they become forgetful, especially in the elderly. Although the elderly are forgetful, their cerebral cortex activity has not stopped. When new conditioned reflexes cannot be established, the previously established and very solid conditioned reflexes appear, thus forming a very clear memory of the past. But recent events are often forgotten.