Poor insight into illness is considered the primary cause of treatment noncompliance in schizophrenia. In this article, we critically discuss the predominant conceptual accounts of poor insight, which consider it as an ineffective self-reflection, caused either by psychological defenses or impaired metacognition. We argue that these accounts are at odds with the phenomenology of schizophrenia, and we propose a novel account of poor insight. We suggest that the reason why schizophrenia patients have no or only partial insight and consequently do not comply with treatment is rooted in the nature of their anomalous self-experiences (ie, self- disorders) and the related articulation of their psychotic symptoms. We argue that self-disorders destabilize the patients’ experiential framework, thereby weakening their basic sense of reality (natural attitude) and enabling another sense of reality (solipsistic attitude) to emerge and coexist. This coexistence of attitudes, which Bleuler termed “double bookkeeping,” is, in our view, central to understanding what poor insight in schizophrenia really is. We suggest that our phenomenologically informed account of poor insight may have important implications for early intervention, psychoeducation, and psychotherapy for schizophrenia.