Inner worlds and subjectivity are increasingly recognized as key dimensions of sustainability transformations. This paper explores the potential of cross-cultural learning and Indigenous knowledge as deep leverage points—hard to pull but truly transformative—for inner world sustainability transformations. In this exploratory study we propose a theoretical model of the inner transformation–sustainability nexus based on three distinctive inside-out pathways of transformation. Each pathway is activated at the inner world of individuals and cascades through the outer levels (individual and collective) of the iceberg model, ultimately resulting in transformations of the individual’s relationship with others, non-humans, or oneself. Our main purpose is to empirically investigate the activation of inner leverage points among graduate students who are alumni of an Indigenous language field school in the Ecuadorian Amazon. Semi-structured interviews designed around three core aspects—(1) human–nature relationships; (2) subjective change; and (3) acknowledgment for Indigenous culture—yielded expressions of becoming aware of new forms of relationships and empirically illustrate the roles of deep leverage points in triggering the three inside-out pathways of our model. A strategic focus on activating inner levers could increase the effectiveness of cross-cultural learning in fostering transformations in relationships with non-humans, oneself and others that may yield sustainability outcomes.