This chapter systematically establishes sleep as an active neurocognitive process essential to memory consolidation, motor learning, emotional regulation, abstraction, and future-oriented simulation. It integrates empirical findings from sleep neuroscience with the book’s conceptual framework, demonstrating how NREM and REM sleep stages differentially support declarative memory transfer, procedural stabilization, emotional recalibration, and creative recombination. The chapter explains hippocampal–neocortical systems consolidation, motor replay, and synaptic optimization as core mechanisms through which sleep transforms transient daytime experiences into stable Neural Assets. Within this framework, the SensemoKinogram (SEKgram) model is extended to sleep, conceptualizing nocturnal processing as a biological pipeline in which sensory–motor–emotional representations are extracted, reorganized, and recompiled under affective modulation. The chapter further situates sleep as a prerequisite for abstraction, insight generation, and pattern discovery, particularly in complex problem-solving and mathematical learning, emphasizing offline restructuring rather than passive storage. By linking sleep-dependent replay, emotional regulation, narrative restructuring, and future simulation, the chapter clarifies sleep’s role in converting experience into durable, flexible, and predictive neural structures. Functionally, this chapter provides the physiological and computational substrate that connects learning, creativity, and performance across the book’s broader model of embodied cognition and Neural Asset formation.