(3.1) Memory mechanism
First, let's learn about the hardware of human memory, that is, brain and nerve. This approach is similar to learning computer architecture to write a good program.
Nonetheless, the purpose of this book is not to nurture researchers in neuroscience, so I narrowed down the information quite considerably. For those who want to know more, I recommend "MEMORY: From Mind to Molecule" and "Principles of Neural Science" by Eric Richard Kandel who won the Nobel Prize in Physiology and Medicine 2000 in the research of nerves.