Little public information is available about Kathy Sierra's early childhood. However, her subsequent academic and professional choices suggest an early interest in the human body and its capabilities. These early experiences likely planted the seeds for her later focus on how people learn and interact with technology.

Kathy Sierra attended California Polytechnic State University, San Luis Obispo (Cal Poly), pursuing a degree in Exercise Physiology. This period was crucial in grounding her understanding of how the human body works, learns, and adapts. This knowledge would later inform her approach to designing engaging and effective learning experiences, albeit in a vastly different domain – software development and user interfaces. The rigorous scientific approach of exercise physiology likely instilled a valuable discipline in her thought process.