Hermann Ebbinghaus was a German psychologist known for his pioneering work in the study of memory. In the late 19th century, he conducted experiments on himself to understand how we learn and forget information. His most famous contribution is the Ebbinghaus forgetting curve, which illustrates how quickly we lose information over time if we do not actively try to retain it. Ebbinghaus also introduced the concept of nonsense syllables to eliminate the influence of prior knowledge on memory studies. By using these meaningless combinations of letters, he aimed to focus solely on the processes of learning and recall, laying the groundwork for modern memory research.