Negativity bias describes the human tendency to assign greater weight, attention, and cognitive resources to negative events over positive ones, even when both are of equal intensity. This chapter illustrates this phenomenon through the story of the initial rejection of laparoscopic surgery in Germany. Despite its advantages such as reduced postoperative pain, faster recovery, and fewer wound complications, pioneers Kurt Semm and Erich Mühe faced extreme skepticism, criticism, institutional obstacles, and even legal proceedings. Fears related to potential complications, perceived technical difficulty, costs, and the need for new skills overshadowed the clear benefits of the minimally invasive approach, delaying its adoption despite clinical evidence. The chapter defines negativity bias, reviews its evolutionary origins and historical development, and analyzes its effects on personal and collective decision-making, including defensive medicine, risk distortion, and error-focused cultures. Concrete examples from surgical practice are presented to illustrate how this bias can hinder innovation and affect clinical reasoning. Finally, practical strategies to mitigate negativity bias are discussed, including reframing, balanced feedback, mindfulness, and the structured evaluation of both positive and negative outcomes.