The self-insight motive (SIM; also known under the label self-assessment motive) describes the dispositional tendency to strive for accurate self-knowledge. The current research includes five multimethodological studies (total N = 3667) that comprehensively investigated the SIM's nomological network, its antecedents, and cognitive-behavioral consequences, comprising longitudinal, round-robin, and population-representative data. Among the personality correlates of the SIM were curiosity, the intimacy and self-improvement motives, private self-consciousness, narcissistic admiration, and openness to experience. Further, the SIM was more pronounced among younger and highly educated people. A key environmental antecedent of the SIM was the instability of life circumstances, in the sense that the motive became stronger after life circumstances had changed. Concerning the cognitive-behavioral consequences, the results suggest that the SIM fosters feedback-seeking behavior. Nevertheless, the motive was not linked to more accurate self-perception across three studies. We discuss several reasons for this unexpected finding. The focus of this research was the self-insight motive (SIM), which is all about wanting to know oneself better. The research involved five studies and a large number of participants (3667 in total). The researchers looked at how the SIM is connected to demography and different personality traits, at whether the SIM gets stronger when significant changes happen in a person's life, and at the behaviors that people with a strong SIM tend to do. It turns out that younger and more educated people tend to have a stronger SIM. Concerning associated personality traits, people tend to have a stronger SIM, when they are generally more curious, want to improve themselves, reflect a lot about themselves, want to be admired, and when they are open to new experiences. Interestingly, when life situations of a person change, the SIM is likely to become stronger. One thing the SIM does is make people seek feedback about themselves. However, surprisingly, it doesn't necessarily make them any better at knowing themselves accurately.