Imagine a world where every fleeting thought and trivial detail were permanently etched into your long-term memory. Your cognitive faculties would quickly become overwhelmed with irrelevant information, hindering your ability to focus on what truly matters. Memory triage is the brain's solution to this dilemma. When we sleep, it selects and strengthens the memories that are most relevant, significant, or emotionally charged while allowing less crucial information to fade away. In our age of information overload and digital distractions, our memory systems are constantly under pressure. As we absorb vast amounts of data daily, our brains must efficiently prioritise what to remember and what to discard. Failure in this process can lead to cognitive overload, reduced productivity, and heightened stress. Additionally, as we age, the quality and duration of our sleep tend to decline. This in turn can affect memory consolidation, a sleep-dependent process, leading to memory problems and cognitive decline. Understanding the mechanisms behind memory triage, and its relationship with sleep, can inform interventions to alleviate these age-related memory issues, enhancing the quality of life for older individuals. In this proposal we will examine neural replay, the spontaneous reactivation of memory traces by the hippocampus, which we hypothesize to be the mechanism central to the memory prioritisation process. We will test our model, where replay activity in the awake state tags important memories that should be prioritised later during sleep, which then increases the amount of replay for this memory during sleep, which speeds up the consolidation process. We will use a combination of optogenetics, electrophysiology, pharmacology, and behaviour to interrogate the relationship between awake and sleep replay, within the context of memory prioritisation.