Children of parents with mental illness (COPMI) grow up with either episodic or enduring mental illnesses within their parents that shape their childhood and impact their entire family. COPMI research is important to the field of child and family psychology as parental mental illness influences child development, parenting experiences, and family functionality. International research on the felt experiences of COPMI and subsequent impacts are well-established in international research with a notable gap on the recent experiences of tertiary students and children in Aotearoa New Zealand who have not engaged with a COPMI service. The study aimed to investigate the childhood experiences among COPMI tertiary students in Aotearoa New Zealand. Participants were five female tertiary students who had grown up in Aotearoa New Zealand and had a parent who had received psychiatric care. Each participant completed a semi-structured interview about their childhood which was transcribed and analysed using reflexive thematic analysis. Three subsequent themes were inductively generated and held together by the metaphor of navigating a tunnel without sight to illustrate how the participants navigated their parent’s mental illness. Each theme had three subthemes which followed a chronological order of their experiences of going from in the dark, growing eyes that see, to lighting a spark. The theme in the dark captured family secrecy about mental illness, inadequate support, and feeling stuck and alone. Second, the theme of growing eyes that see described their journey towards understanding as they experienced hypervigilance, a desire to understand, and positive outcomes. The final theme lighting a spark illustrated the felt connection between the past and the present as the participants felt the impacts of parental mental illness on the family system, talking and education helped, and they had a desire for change. Ultimately, the childhood experiences of COPMI had a profound and long-term impact, providing motivation and inspiration amongst their ongoing loss, frustration, and difficulties. The implications are relevant for a range of people, such as COPMI and their families, practitioners, and policymakers, with avenues for future research that are outlined for researchers.