This document discusses the importance of learning lessons from projects and the roles a Project Management Office (PMO) can play in facilitating effective lessons learned. It notes that while lessons learned are important, they are often not captured, stored, or applied effectively for various reasons such as lack of reflection, unwillingness to share knowledge, and the belief that each project is unique. The document provides examples of why lessons learned are important and offers suggestions for how PMOs and organizations can improve reflection, capture, storage, retrieval and application of lessons to help ensure knowledge is shared and learning occurs across projects.