This paper considers the landscape of early childhood education in England to be dominated by discourses of "readiness-for-school" and "readiness-for-learning" that act to heavily stratify the educational spaces inhabited by young children. The "ready-child" is constructed as a normative identity towards which the "unready" child is expected to progress. This is not to imply that "readiness"/"unreadiness" is constructed as a binary relationship, but rather that "readiness" is predominantly understood as a predefined spectrum of knowledge, skills and identities. This paper considers the confinement of children within such predetermined subject positions to be problematic, as inevitably not all children will achieve these normative ideals or progress across this spectrum in a recognizable manner, resulting in their exclusion from positions of "success". In response to these concerns, this article seeks to disrupt dominant conceptualizations of "readiness" in the context of early childhood education, expanding space for alternative ideas, theories and practices. In a deliberate move away from concepts that relate "readiness" to predefined goals, outcomes and identities, the possibility of thinking with a complex logic in order to generate new ideas, understandings and practices is explored. Approaching complexity from the "outside-in", this paper draws in particular on the concept of "becoming" (Deleuze & Guattari, 1987), exploring "readiness" as a complex process of emergence, always open to the unpredictable and the new. It is argued that "readiness" is part of an open-ended "becoming", rather than a pre-defined "state" of being. Drawing on the work of Deleuze (1983), Deleuze and Guattari (1987) and Dewey (1899/2010; 1916), this reconceptualized idea of "readiness" does not hark back to romantic notions that might consider all forms of development equally valid or desirable. This paper argues instead that it matters greatly what and how children "become" and as such, "readiness" for these emergent "becomings" must be considered an ethical and political endeavor.