Background/Context: A growing body of literature addresses the experiences of transnational students, but relatively little research has focused on students who negotiate international border crossings on a regular basis. This study documents the role of cross-border mobility in the lives of university students in Brownsville, Texas (U.S.)/Matamoros, Tamaulipas (Mexico) and links students' transnational experiences to their development of critical cosmopolitan identities and perspectives. Purpose/Objective/Research Question/Focus of Study: This study explores South Texas university students' lived experiences of cross-border mobility at a time of sociopolitical upheaval in the U.S.-Mexico borderlands and illuminates how specific forms of mobility can shape students' educational and social subjectivities. Research Design: An insider-outsider researcher and two undergraduate insiders collaborated to design and implement the study. An online survey was used to gather basic information about students' cross-border mobility and educational experiences; subsequently, 16 focal participants were selected to participate in ethnographic interviews. Interview data were analyzed in NVivo using a two-cycle coding process and triangulated with survey data. Findings/Results: Cross-border mobility offered academic and social benefits to the participants, but the benefits of mobility were inextricable from its drawbacks. Participants acknowledged the everyday difficulties associated with cross-border mobility; they also believed that these difficulties made them more responsible and successful. In addition, while participants spoke openly about the impact of violence on the borderlands, having to navigate this reality allowed them to develop a powerful form of insight connected to "knowing two versions" (one from each side of the border) of events. Conclusions/Recommendations: The results invite researchers and educators to engage more critically with the cosmopolitan voices of students from areas often regarded as sites of marginality, poverty, and violence, such as the U.S.-Mexico borderlands. Participants' cross-border experiences simultaneously challenged and benefited them; these experiences gave them opportunities to construct, traverse, and inhabit a wider range of emotional geographies where they could make sense of their relationships to people, events, and places on both sides of the border.