The human knee has a complex evolutionary history, shaped by the need to walk upright and differentiate us from our extinct relatives. While evolution has helped us walk efficiently, our modern sedentary lifestyles have led to knee problems like osteoarthritis, which were not prevalent in our hunter-gatherer ancestors. The presence of sesamoid bones, like the fabella, adds another layer of complexity, suggesting a unique evolutionary path for humans. This article explores the surprising twists and turns of knee evolution and how our modern lifestyles are impacting this crucial joint.