This retrospective phenomenological study investigates activities and actions identified by secondary statistics teachers who exhibit robust understandings of variation as deepening their understandings of statistical variation. Framed by Mezirow’s transformation theory, analysis revealed learning factors that include interest in the field of statistics, motivation to encounter and resolve dilemmas, reflection on content, and opportunities to engage in learning and rational discourse. The extent to which these teachers seek and embrace learning opportunities may distinguish them from other teachers. This work contributes to understanding circumstances that may be conducive to developing deep understandings of statistical content. It also advances the use of retrospective methods within a theoretical frame for adult learning to investigate teacher learning.