This article examines how trust is built and maintained in interpersonal care relations between people diagnosed with dementia and their vocationally trained care assistants in a Danish welfare context. The issue of trust is singled out as being particularly relevant, as people diagnosed with dementia often possess different cognitive abilities than those most commonly mentioned within existing social theory and research as prerequisites for building and maintaining trust in interpersonal care relations. The article is based on ethnographic fieldwork conducted in various locations in Denmark, primarily during the summer and fall of 2021. It argues that in order for care assistants to build trustful relations with people diagnosed with dementia, they need to acquire the ability to set the “tone” or the “mood” of the care interactions, as that makes it possible to step into the world of people diagnosed with dementia in ways that acknowledge fundamental human affectedness as captured in Heidegger’s notion of “being-in-the-world.” Put differently, the social aspects of caregiving should not be separated from the specific nursing tasks that need to be performed. Rather, they should be considered prerequisites for providing those tasks in the first place.