What can senior practitioners teach other practitioners about learning arenas for professional development? Four primary learning arenas were identified after a qualitative inquiry of 12 psychotherapists, averaging 74 years in age. The 4 learning arenas are early life experience, cumulative professional experience, interaction with professional elders, and experiences in adult personal life. The results indicate that profound experiences in any of these primary arenas can radically affect the professional work of the practitioner. To develop optimally, the practitioner needs to continually process and reflect on experiences in both personal and professional life domains.