Initial-State Dependence of Thermodynamic Dissipation for any Quantum Process

New exact results about the nonequilibrium thermodynamics of open quantum systems at arbitrary timescales are obtained by considering all possible variations of initial conditions of a system, its environment, and correlations between them. For any finite-time process with a fixed initial environment, we show that the contraction of the system's distinction---relative to the minimally dissipative state---exactly quantifies its thermodynamic dissipation. The quantum component of this dissipation is the change in coherence relative to the minimally dissipative state. Implications for quantum state preparation and local control are explored. Notably, we establish the impossibility of Landauer's bound for almost every input to any reset protocol. For nonunitary processes---like the preparation of any particular quantum state---we find that mismatched expectations lead to divergent dissipation as the actual initial state becomes orthogonal to the anticipated one.