Willingham also introduces in his book the concept that, "Memory is the residue of thought." This means that we remember most what we think about most. If the students are interested and inspired to think about things for prolonged periods, then memory is enhanced. This is where inquiry, constructivism, and curiosity come into play -- providing opportunities for students to think about what they are learning. In this way, memory is improved, students do better on standardized tests, and, guess what? Students enjoy learning! Problem solved.