The word ``memory'' is misleading. Being a single word, it creates the impression that it refers to a single entity. The same criticism applies to most of the terms of naive psychology, such as intelligence, or self. Only after one tries to understand the workings of memory, that one realizes the inadequacy of this common sense notion. Memory is not unitary. There are many dimensions along which different types of memory can be classified. Memory does not exist at a single place. It seems like almost every sub-system in the brain has its own memory. In some sense, memory should be an adjective, rather than a noun, denoting a quality that a particular system may or may not have.
Being such a diffusely linked union of mechanisms, how did people come up with such a concept and initiate research efforts to understand it? Maybe it is not because people are bad at creating concepts, in fact they are the best at that in the world. It is because of this miraculous illusion, a sense of unity that one subjectively feels, when one thinks about how his mind works. If one has a fully functional mind, most of the time one does not realize how effortlessly the important details of the life are stored, how just the relevant information is retrieved when a problem is to be solved. It is only after something breaks down that this illusion goes away, and we start seeing the signs of the interlocked mechanisms, normally working together in harmony, to create this illusion of memory for us.
It is said that learning is the crown of intelligence. After all, computers are performing complex computations everyday, that would take people years to complete. However, even the best performing chess program does not get any better from one game to the next. It is this potential of learning, the ability to excel in any field we choose, that makes us intelligent. And learning is what memory does. Thus for a full understanding of how the mind works, it is essential to solve the mysteries of memory.