This paper outlines the use of a new qualitative research approach, Co-Constructed Inquiry, to develop a personal theory of the experience of living and adjusting to an early diagnosis of Alzheimer's disease. The personal theory was developed over a 21-month period (March 2004—December 2005) between Sarah, a person with Alzheimer's disease, and a clinical nurse specialist at a memory clinic in North Wales, John Hughes-Roberts. The resulting work suggested that Sarah co-constructed her experience of living with the onset of Alzheimer's disease as a process of `making mistakes' and that her life story was a powerful influence in mediating and enhancing her coping behaviour. Moreover, a sequence of `balancing' acts, i.e. losing balance — finding balance — keeping balance, which Sarah visualised as the `up and down' motion of a see-saw, both conceptualised and diagrammed her early adjustment experience. Sarah's personal theory has implications for practice and research development.