Carl Jung, a prominent Swiss psychiatrist who lived from 1875 to 1961, has been the subject of intense debate regarding his mental health, especially after his mid-thirties. The publication of his seven-volume journal, the Black Books, provides new insights into his experiences, revealing Jung's encounters with hypnagogic-hypnopompic experiences, hyperphantasia, hallucinations, personifications, and sensed presence. Contrary to claims of psychosis by his contemporaries and some biographers, recent research suggests that Jung's experiences were a result of his extremely vivid mental imagery, known as hyperphantasia. This condition, not recognized in his time, involves mental imagery so vivid it becomes almost indistinguishable from reality. Jung's ability to contextualize and find meaning in his perceptual experiences without losing touch with reality suggests that his experiences were not indicative of a psychotic disorder but were manifestations of his profound imagination and introspective explorations. His work, particularly his concept of "reality equivalence," foreshadowed modern investigations into the vividness of mental imagery and its impact on perception. Jung's life exemplifies the fine line between profound psychological insight and the edges of perceived reality, demonstrating how extreme vividness of imagination can enrich understanding without necessarily implying psychopathology.