Survivorship bias is a cognitive distortion that arises when only the successful or visible cases of a process are analyzed, while those that did not “survive” or were not recorded are ignored, leading to erroneous, overly optimistic, and unfounded conclusions. This chapter illustrates the phenomenon through the history of Robert Battey and the so-called normal ovariotomy, a procedure that, driven by partial observations and reinforced by clinical desperation, professional prestige, and a cultural climate attributing numerous female diseases to the ovaries, was performed on thousands of women during the nineteenth century. The chapter examines how Battey, despite being aware of the high operative mortality and limited effectiveness of the procedure, continued to consider it successful by focusing almost exclusively on the few “favorable” cases that confirmed his expectations. The historical origins of survivorship bias are reviewed, from Abraham Wald’s work during World War II to contemporary studies on sample selection and incomplete reasoning. The personal, collective, and clinical consequences are also described: overestimation of success rates, underestimation of risks, creation of biased historical narratives, and significant errors in medical decision-making. Finally, strategies to mitigate this bias are presented, including comprehensive data analysis, appropriate statistical techniques, external feedback, and a culture that values both successes and failures.