0-6 months of age. In the earliest stage of development, you were dominated by a chaotic mix of perceptions, feelings, and needs. You did not distinguish your own self from that of your parents or even the world around you. Rather, you spent your time taking into yourself everything that you experienced as pleasurable without any acknowledgment of boundaries. This is the stage, then, when you were closest to the pure materiality of existence, or what Lacan terms "the Real." Still, even at this early stage, your body began to be fragmented into specific erogenous zones (mouth, anus, penis, vagina), aided by the fact that your mother tended to pay special attention to these body parts. This "territorialization" of the body could already be seen as a falling off, an imposition of boundaries and, thus, the neo-natal beginning of socialization (a first step away from the Real). Indeed, this fragmentation was accompanied by an identification with those things perceived as fulfilling your lack at this early stage: the mother's breast, her voice, her gaze. Since these privileged external objects could not be perfectly assimilated and could not, therefore, ultimately fulfill your lack, you already began to establish the psychic dynamic (fantasy vs. lack) that would control the rest of your life.
6-18 months of age. This stage, which Lacan terms the "mirror stage," was a central moment in your development. The "mirror stage" entails a "libidinal dynamism" (Écrits 2) caused by the young child's identification with his own image (what Lacan terms the "Ideal-I" or "ideal ego"). For Lacan, this act marks the primordial recognition of one's self as "I," although at a point "before it is objectified in the dialectic of identification with the other, and before language restores to it, in the universal, its function as subject" (Écrits 2). In other words, this recognition of the self's image precedes the entrance into language, after which the subject can understand the place of that image of the self within a larger social order, in which the subject must negotiate his or her relationship with others. Still, the mirror stage is necessary for the next stage, since to recognize yourself as "I" is like recognizing yourself as other ("yes, that person over there is me"); this act is thus fundamentally self-alienating. Indeed, for this reason your feelings towards the image were mixed, caught between hatred ("I hate that version of myself because it is so much better than me") and love ("I want to be like that image").Note This "Ideal-I" is important precisely because it represents to the subject a simplified, bounded form of the self, as opposed to the turbulent chaotic perceptions, feelings, and needs felt by the infant. This "primordial Discord" (Écrits 4) is particularly formative for the subject, that is, the discord between, on the one hand, the idealizing image in the mirror and, on the other hand, the reality of one's body between 6-18 months ("the signs of uneasiness and motor unco-ordination of the neo-natal months" [Écrits 4]): "The mirror stage is a drama whose internal thrust is precipitated from insufficiency to anticipation—and which manufactures for the subject, caught up in the lure of spatial identification, the succession of phantasies that extends from a fragmented body-image to a form of its totality that I shall call orthopaedic—and, lastly, to the assumption of the armour of an alienating identity, which will mark with its rigid structure the subject's entire mental development" (Écrits 4). This misrecognition or méconnaissance (seeing an ideal-I where there is a fragmented, chaotic body) subsequently "characterizes the ego in all its structures" (Écrits 6). In particular, this creation of an ideal version of the self gives pre-verbal impetus to the creation of narcissistic phantasies in the fully developed subject. It establishes what Lacan terms the "imaginary order" and, through the imaginary, continues to assert its influence on the subject even after the subject enters the next stage of development.