Teachers focus on developing students’ conscious learning and understanding of concepts, but there is a whole other dimension of mental life that teachers also influence: implicit thought and memory. Psychologists distinguish between explicit and implicit mental processes.[1] We are consciously aware of explicit processes, as when we rehearse information or think through a problem. Implicit knowledge and skills are not consciously available to us, but our behavior expresses them. An example is reading. We can’t explain how we read, but we can demonstrate it. When we teach, we influence implicit processes as well as explicit ones, so we need to understand implicit learning and memory. There are several types of implicit processes relevant to teaching.