Larry Swedroe and Kevin Grogan introduce their 2019 book, Your Complete Guide to a Successful and Secure Retirement, as follows: “…failure to plan is to plan to fail. While so many of us have carefully planned our education, career choices, and family responsibilities, we tend to fail to prepare a written retirement life plan that considers, among other things, our passions, financial security, charitable endeavors, relationships, intellectual stimulation, and having fun. …Having a well-thought-out plan is important. However, planning is not a one-and-done event. To be effective, plans must be living things that must be revisited whenever any of the assumptions upon which the plan was based have changed.”