Since his publications began to appear in the mid 1980s, Mark Ylvisaker has shaped the way clinicians worldwide approach brain injury rehabilitation. His body of work reflects his exceptional ability to draw together theories, ideas, and practices from multiple disciplines and paradigms culminating in the development of a clinically powerful framework to facilitate change in behavior. The focus of this article is two core aspects of Mark Ylvisaker's work that have had a significant impact on my own work. These aspects involve (1) using conceptualization of self or identity construction as a guide for developing rehabilitation goals and (2) centralizing meaningful activity within the intervention process. In a small way, this article is a tribute to an exceptional man who was dedicated to improving the lives of people with brain injury and in doing so succeeded in improving the lives of all who had the privilege of knowing him and knowing his work.