There is a growing body of evidence in support of sleep-dependent memory consolidation and plasticity. However, there are also examples of memory development and plasticity in the absence of sleep, casting doubt on an exclusive sleep-dependent memory hypothesis. As a result, polarized stances have arisen within the field. Here we reflect on these findings, and explore how they maybe reconcilable in a unified approach to understanding the roles of wake, sleep and specific sleep stages in successful memory processing and brain plasticity.