The field of water resources systems analysis is now experiencing one of its most exciting eras where scientists, decision makers, and funding agencies want to apply systems approaches to solve varied, complex, uncertain, and interdisciplinary resource management problems. Solving these problems presents great opportunities for us to engage in complex, real-world decision-making and make positive changes. However, to capitalize on these opportunities, we as a field must also overcome several large challenges related to problem identification, integration, blind use of systems tools, a focus on optimality, and harnessing big data. To overcome, we must look back to find what we have accomplished, why we have sometimes failed, and how we can improve upon past work.