How do neural circuits in the brain accomplish rapid learning? When foraging for food in a previously unexplored environment, animals store memories of landmarks based on as few as one single view. Also, animals remember landmarks and navigation decisions that eventually lead to food, which requires that the brain associate events with delayed outcomes. I will present evidence that a particular neural circuit structure found in the hippocampus and cortex enables exactly this type of one-shot learning across a delay. The learning mechanism requires active computations in neuronal dendrites, and is potently controlled by synaptic inhibition from local interneurons. I will also discuss potential implications of this unique form of plasticity for understanding memory deficits associated with neurological disorders.