Daily function depends on an ability to mentally map our environment. Environmental visibility and complexity can increase this challenge. Importantly, people vary dramatically in their ability to navigate flexibly and overcome such environmental challenges. In this paper, we will present experimental work targeting the mechanisms that underlie different navigational abilities, and how objective and introspective measures of ability interact to influence navigational strategy use. Using virtual reality, we manipulated environmental visibility and complexity. Participants then performed wayfinding, pointing, and route following tasks to probe cognitive map memory and navigational flexibility. Our findings reveal that individual differences in metacognition - such as perceived sense of direction - and in navigational strategy preference powerfully impact how environmental features affect spatial memory. We also gathered data on the neurocognitive foundations of these differences. Importantly, our methods highlight individualized interventions that can improve spatial learning and specify the mechanisms through which they operate.