This work introduces dreaming not as a psychological metaphor, but as a real dynamical regime of complex systems. Building on the Resonance Architecture framework, the paper shows that dreaming corresponds to a phase in which a system temporarily loosens stabilizing constraints and enters a state of resonant expansion. In this regime, the system does not collapse into noise, but instead explores new coherent configurations that are inaccessible in strictly stable modes. Through thirteen cross-scale examples — spanning physics, biology, cognition, language, music, social systems, and artificial intelligence — the work demonstrates that dreaming is a universal bifurcation mechanism. It allows systems to transition from rigid or saturated states into new attractor structures while preserving coherence. Dreaming is presented as a necessary condition for innovation, adaptation, and the emergence of new structure. It is neither error nor randomness, but a controlled expansion of internal degrees of freedom under resonance. This paper positions dreaming as a fundamental generative process underlying the evolution of complexity, linking physical transformations, cognitive flexibility, and the future development of artificial intelligence within a single, scale-invariant framework.