The value of the continuing education industry for therapists is questioned, as is the usefulness of therapy books and journal articles, as a means of engaging therapists in life-long learning. Instead, it is argued that our clients are our best teachers and that therapists learn most effectively from their clients. Drawing on research studies with prominent theoreticians and therapists, and on case studies from clinical work, a number of important themes are identified as ways in which therapists are influenced by their therapeutic encounters with their clients. The themes explored in this article include: (1) intimacy and high emotional arousal with clients as we witness profound change; (2) being challenged by clients; and (3) allowing for boundary 'crossings' in order to develop more flexible ways of working with clients. The implications for professional development are discussed.