This introduction to this issue of JCLP: In Session (“Reflections of Senior Therapists”) focuses on the multifaceted ways in which adult development influences what it means to be a psychotherapist and to do the work of psychotherapy. This issue brings together first person narratives written by a group of eminent psychotherapists as well as an empirical report, based on a major international survey, on the challenges, demands, and rewards experienced by senior therapists. Taken together, these essays provide a compelling case that not only can practicing psychotherapy during the later years of one's life continue to be fulfilling and meaningful, but also the lessons learned along the journey can make one an even wiser and more effective therapist than previously. Learning to do psychotherapy, like adult development itself, is not a process that at some point comes to an end, but one that is resumed again and again in every decade. These essays provide a rich array of information, insight, and guidance regarding the personal and professional experience of practicing therapy during every era of adulthood, including one's senior years.