Case conceptualization is a primary skill that may be the linchpin of clinical practice as it sets the framework for making sense of a patient’s difficulties and guides a path toward change. Providing meaning and structure to often ambiguous and nuanced clinical information, an apt case conceptualization facilitates the therapist’s complex integration of core therapeutic skills to produce expert performance. Rooted in the cognitive sciences literature on expertise, we introduce the concept of metabolizing theory to capture expert therapists’ capacity to use theoretical and clinical knowledge in an intuitive, flexible manner that responds and adapts to the unique and complex context of the treatment.