Mental health nurses undertake difficult and complex roles. Therapeutic relationships and engagement between mental health nurses and people experiencing severe mental ill‐health provide the core purpose and rationale for such mental health care. These relationships are influenced by factors outside of frontline mental health nurses control. They are difficult to define or describe with clarity, have limited ‘quantitative’ evidence of effectiveness and are frequently not experienced as therapeutic. This paper presents some initial ideas regarding ‘everyday ordinariness’ using psychologist Daniel Kahneman's two systems of thinking as a focus for understanding and potentially improving mental health nurse practice, and therapeutic relationships and engagement.