In this paper, I talk about several issues in regard to self and consciousness. I do so from a developmental perspective, since such a perspective may provide a framework to help understand consciousness as seen in the adult human. Briefly, the two processes I will call the machinery of the self and the mental state of the idea of me develop over the first two years of the child's life. Moreover, and perhaps of equal importance is the fact that the development of consciousness (the idea of me) provides the scaffolding for the development of the child's social and emotional development and is the first step in the child's development of other mental states, which provide the underpinning of a theory of mind. I will first explore what a self is and what it is not; then I will present a developmental model that provides a way of measuring early the idea of me or consciousness. Having shown how to measure this mental state, I will show how it has an impact on the development of a theory of mind, as well as on the child's emotional and social life. Finally, I will turn to the emergence of explicit and implicit consciousness.