During the initial stage of life, infants are unaware of their unique existence and do not possess self-awareness. This lack of recognition of self is evident when an infant gazes at their own hand but does not understand it belongs to them. Around 18 months, self-awareness begins to materialize; this is tested through experiments like the 'mirror test,' where infants with sufficient self-recognition will touch a mark on their own cheek instead of the mirror. By the latter half of the second year, infants start using personal pronouns such as 'I', 'me', or 'mine', indicating a growing understanding of their individuality and possession. Factors such as parental interaction and social exposure play significant roles in this developmental stage.