The myriad and contested meanings of ‘sustainability’ and ‘sustainable development’ lead many to refer to both concepts as meaningless, oxymoronic, and paradoxical. Yet breaking down such terms to their key principles allows for introducing core concepts, constituent meanings, and associated practices that should enable greater understanding. Despite this, understandings of the interconnected nature of sustainability and sustainable development lack a holistic perspective among students. Exploring this area further, this paper presents findings from a 6-year longitudinal survey at Southern Connecticut State University which asked sustainability studies students (n = 150) for their perspectives on the Rio Declaration’s principles of sustainability. Findings from this study elucidate the many disconnections students form predicated on limited real-world global awareness of sustainability projects alongside breaking down broad concepts to those accommodated by contemporary socio-environmental discourse. Conversely, sustainability students consider alternative concepts such as responsibility, cooperation, accountability, intersectionality, and new economic pathways to be of value and necessity as opposed to the sustainability principles encompassed in the Rio Declaration. Summarising the alternative concepts that are preferable to sustainability students, and exploring the principles and implications of related disconnections and terminological evolution, this article argues for increasing engagement from sustainability academics to explore this departure from some of the discipline’s core foundations.