In this conversation, we begin with fundamental coursework in brain biology—including its architecture and energy systems. We go on to discuss what these systems look like when something goes wrong and cognitive decline ensues. We talk about the evolutionary origins of the ApoE genotype, with specific attention to the ApoE4 allele and its association with AD. We spend time discussing ApoE4 implications for the brain’s fuel utilization, notably omega-3 fatty acids: EPA and DHA. We briefly pivot to the implications of recent omega-3 trials for cardiovascular disease and return to what we currently understand about EPA/DHA and brain health; we contemplate potential dietary interventions across the lifespan to preserve and prolong cognitive function.