Consolidated memories can re-enter states of transient instability following reactivation, from which they must again stabilize in order to persist, contradicting the previously dominant view that memory and its associated plasticity mechanisms progressively and irreversibly decline with time. We witness exciting times, as neuroscience begins embracing a position, long-held in cognitive psychology, that recognizes memory as a principally dynamic process. In light of remaining controversy, we here establish that the same operational definitions and types of evidence underpin the deduction of both reconsolidation and consolidation, thus validating the extrapolation that post-retrieval memory plasticity reflects processes akin to those that stabilized the memory following acquisition.