Children and adults are notoriously poor at remembering mechanistic information. As a result, teaching mechanism has come under increasing scrutiny in science education. However, while a rich memory for mechanistic details may be out of the average student’s grasp, we argue exposure to mechanism does not leave students empty-handed. Instead, it refines their intuitions about science and the world in significant ways. In this study, we focused on one particular kind of intuition: causal complexity. Children ages 6-11 rated the complexity of two entities and were then given either mechanistic or non-mechanistic information about them. We tracked the evolution of their intuitions about complexity immediately after and three weeks later. Children in the mechanistic condition demonstrated a greater shift compared to the non-mechanistic condition. This contradicts the notion that mechanism provides learners with few benefits, while also demonstrating how mechanism can be a powerful force in shaping children’s intuitions.