Memory is a basic human ability that allows us to recall past events and knowledge. It is a concept whose importance stems from the fact that our understanding of time is one directional, forward, and all of our current actions depend upon the past knowledge and future expectations. It is no accident that the our word for memory is derived from the ancient Greek myth of Mnemosyne, the mother of the Muses who was "said to know everything, past, present, and future."  Indeed, memory is essential to our existence and impossible to underestimate its importance, without memory we would not be able to perform basic functions or have abstract thought. Moreover, it is through our concept of the past that we are able to create our own identities and communicate with others. Through memory able learn how to create and comprehend what is presented; in this respect it is the starting point of media.
Generally, memory can be understood as follows: 1. The process and/or processes of remembering past thoughts and actions. 2. A recollection, or remembrance. 3. A device that data or program instructions may be stored and from which they may be retrieved (generally in computers or artificial intelligence).  It is action or series of actions in remembering, the recollection itself, and the aid that stores the past. It is both internal and external, natural and artificial.
As previously stated, the memory is what allows us to perform tasks, and remember past events, and it is those past events that help to shape us. It is through our memory that we are able to remember our own personal history, the history of our society, and thus come to terms with our place in society. In the chapter entitled "Narrative, Memory, and Slavery," from W. J. T. Mitchell's Picture Theory , memory in terms of both the ability to remember (definition 1) and the recollection itself (definition 2) is considered with regard to how we are able to understand the self, society, and the memory of slavery and oppression. In the first few pages he states that "my subject . . . is not 'slavery itself,' but the representation of slavery in narrative memory."  Mitchell makes a point that in recalling memories of the past there is a separation, a distancing, between the self and former self, yet despite this division the two are interrelated. The former self determines the present self. He also notes the importance of the current self, suggesting that the gaps and filters in memory, both unconscious and conscious attempts to forgot past incidences, in order to protect the current self.
In recalling the past and sharing past experiences the individual narrating the story of his life is both considering his own memories on and individual basis and passing on his memories to other people. He is re-articulating his personhood through his past and the only thing that a slave could truly own. Thus memory as Mitchell sees it is "a technology for gaining freedom of movement in and the mastery over the subjective temporality of consciousness and the objective temporality of discursive performance."  Memory allows for the telling of stories and the understanding of them. The stories that we share, both as fictitious and real, are nothing but a layering of information, a dependency of new events and actions on the previously learned events and actions. Narratives require us to remember the characters, the events and actions that took place previous to the point that we are in the story. Without the capacity to remember the early part of the story, the events that are unfolding have no importance to us, the choices the characters make have no consequence, and we are unable to hold any interest in the story. As illustrated in the movie Memento, where the main character Leonard "Lenny" Shelby has a damaged short-term memory, making it impossible to create new memories, the ability to remain attentive to a conversation, television show, or book is impossible.
The film Memento is an interesting point to consider, especially with regard to the idea of memory and identity as illustrated in Mitchell's discussion of narrative. In the movie Leonard attempts to gain control over his situation by devising a system of recording to substitute for his memory. He relies on information he has written down on paper, photographs, and tattoos to record his situation, yet despite the scrutiny with which he attempts to documents his life, he is completely ill equipped to make decisions or act with a clear purpose. He lacks fully awareness of his situation, is ignorant of people's motives. Furthermore, he is unable to have affection for those around him. Leonard remains caught in the past, because he cannot develop a concept of himself separate from his former self; he is forever caught in past goals that are no longer relevant. Mitchell observes that "memory, like description, is the servant of narrative and of the narrator's identity,"  while Leonard exemplifies the fact that without memory's help identity cannot be fully constructed.
There is an understanding that our past has made us, and that our memories belong to us. There is a sanctity to our memories; they have value. It is not just the comprehension and enjoyment of narration that is dependent upon memory, but the very act itself of narration that is bond up in the idea of memory. Whether it be a simple conversation where one person is telling another about his day or a masterpiece in literature, the process of remembering (definition 1) so that it is possible to share and the specific recollection (definition 2) being shared is present and necessary. Furthermore, many books begin with the idea that the events are not taking place, but have taken place. Jane Eyre, The End of the Affair, Brideshead Revisited, Romeo and Juliet, Beloved, The Woman Warrior, -- even the Bible, are all records of past events, they are memories. Furthermore, in many of these books, there is an idea that there is sanctity to those memories. The subtitle of Waugh's Brideshead Revisited reads "the Sacred and Profane Memories of Captain Charles Ryder," cluing the reader into the fact that they are reading a recollection of past events and that there is something special about them. They are the memories of a specific person, and belong to him alone.
The understanding that the process of memory occurs naturally within the human mind is quite modern and goes against the classical belief that viewed memory as an art. While modern psychologists attempt to understand the way that the mind sorts through the information it receives, retaining certain pieces unconsciously without any control or reason, memory as it was conceived in antiquity was planned and controlled. Mitchell argues that memory is media for the fact that "since antiquity, memory has been figured not just as a disembodied, invisible power, but as a specific technology, a mechanism, a material and semiotic process subject to artifice and alteration."  Memory was a technique that allowed an orator to remember long speeches with perfect accuracy. It was a media that combined "the same modalities (space and time), the same sensory channels (the visual and aural), and the same codes (image and word)."  Memory was understood through associations with place and position, and images found in architecture, and relying on sight. It was through "seeing the places, seeing the images stored on the places, with a piercing inner vision"  that an orator was able to recite his speech. Thus the sharing, the externality was important not only in the process of remembering, but also in the motivation for the remembering.
Memory in the story given to us by Cicero was a rhetorical skill that relied on visual stimuli as a device for remembering. Like the memories on our computers (definition 3), architecture stored information. As if something within the external world could hold on to our memories. This idea is later echoed in the legend of the origin of painting. "According to the legend, drawing was discovered by the daughter of a Corinthian poster. About to be separated from her lover, she discovered that she could preserve his likeness by tracing the outline of his shadow cast on the wall."  Later, her father, a potter, transferred this shadow drawing into a sculpture. In both instances of this story, "these Arts seem to have proceeded out of a desire of prolonging the memory of the deceased, or else of them whose absence would be most grievous unto us without such a remembrance."  Thus art can and was viewed as a type of memory, a physical device by which the ephemeral could be made eternal. Like the memory found in our computers, architecture, painting, and, of course, writing are devices by which data could be stored. Writing has been previously alluded to with regard to the idea of narration and literature, however the idea of written language as a storage has not been fully discussed.
Writing can be viewed as a record of the past, a storage device used to grasp hold of past events, actions, or thoughts, yet this tool has problematic implications for some. In Plato's Phadrus, Socrates argues against writing for those who write "will not use their memories, they will trust to the external written characters and not remember themselves."  Socrates fears not only that humans will loss their capacity for being able to remember, but also that writing lacks the power of the spoken word [see speech]. On the page the words and ideas "are tumbled about . . . and know not to whom they should reply, to whom not,'  he fears that they will be misunderstood. Separated from the speaker, words are vulnerable to misunderstanding. Written language is lifeless, dead, a sentiment later echoed by Friedrich Kittler. Kittler viewed writing, and indeed many medias, as a storage device, a record of the past. To him a "book . . . coincides with the realm of the dead,"  a time that is no more, except within these records.
Information and the retention of that information is of the utmost importance in our lives, thus our dependency on memory cannot be overestimated. It forms the building blocks with which we are able to understand the world around us, and identify ourselves as a separated being from those around us. In many instances, though not always with positive connotations, media acts as a device for memory. Though it may not be a media, like television, film, or paint, it is arguably the starting point for much of our media and communication systems.