Research on autism spectrum disorder (ASD) and on Alzheimer's Disease (AD) and other types of dementia describes a behaviour called 'wandering', a term that denotes movement through space lacking intention or exact destination, as when a person is disoriented or not self-aware. In the U.S., 'wandering' in both ASD and AD has been examined mostly from a management and prevention perspective. It prioritizes safety while primarily overlooking personal experiences of those who 'wander' and their families, thus limiting the range of potentially effective strategies to address this issue. Communicative challenges faced by many people diagnosed with ASD and AD further obscure the experiential, existential aspects of 'wandering'. This article reflects an increasing concern of social science scholars interested in whether and how the conceptual and practical strategies to address 'wandering' are informed by the situated experiences of people with cognitive and developmental disabilities and their families. We examine 'wandering' at the intersections of personal experience, family life, clinical practice, public health policy, and legislation, as a conceptually rich site where notions of personhood, subjectivity, intentionality, and quality of life powerfully and consequentially converge to impact the lives of many people with ASD and AD, and their families. We draw upon critical autism studies describing how attributions of personhood, subjectivity, intentionality, rational agency, and moral autonomy of people with ASD have been contingent upon the norms and conventions governing movement of the human body through space (Hilton, Afr Am Rev 50(2):221-235, 2017). When this movement is deemed aberrant, the person may be construed as irrational, a danger to self because of a lack of self-awareness, and a danger to others because of a lack of empathy. These attributions put the person at risk of being excluded from the considerations and, more importantly, the obligations of the 'moral community' to ensure that he or she has a 'good human life' (Barnbaum, The Ethics of Autism: Among Them but not of Them. Indiana University Press, Bloomington, 2008; Silvers and Francis, Metaphilosophy 40(3/4):475-498, 2009). Using ethnographic, narrative phenomenological (Mattingly, The Paradox of Hope: Journeys through a Clinical Borderland. Berkeley: University of California Press, 2010), and medical humanities (Charon, JAMA 286:1897-1902, 2001; Narrative Medicine: Honoring the Stories of Illness. New York: Oxford University Press, 2006) approaches, we examine multiple perspectives on 'wandering' in ASD and AD across narrative discourse genres, institutional contexts, and media of representation. We argue for an extension of the prevention and management view to focus not only on safety but also on what phenomenologist Merleau-Ponty (1962) called "having a world" (p. 146). The analysis is intended to inform clinical practice, policy and public health efforts to enhance understanding of first and second person perspectives on 'wandering' in order to improve the participation and quality of life of people with ASD and AD who 'wander', and their families.