Meaning: The quote you provided comes from Hermann Ebbinghaus, a pioneering psychologist known for his work in the field of memory and learning. Ebbinghaus is often credited with being one of the first psychologists to conduct systematic and controlled experiments on human memory, and his work laid the foundation for the study of memory and learning in the field of psychology.

In this quote, Ebbinghaus is referring to the idea that information that is learned with difficulty is better retained. This concept is often referred to as the "spacing effect" or "distributed practice," and it has been studied extensively in the field of cognitive psychology. The spacing effect refers to the finding that distributing learning over time, with multiple study sessions spaced apart, leads to better retention of the material compared to massed practice, where all the study sessions occur in a short period of time.

Ebbinghaus's own research on memory and learning provided empirical support for this idea. In the late 19th century, he conducted experiments in which he memorized lists of nonsense syllables and then tested his retention of the material at various time intervals. His results showed that the amount of material retained increased as the number of repetitions of the material increased, but the rate of increase diminished with each repetition. This led Ebbinghaus to conclude that the spacing of repetitions had a significant impact on memory retention.

Ebbinghaus's findings have been replicated and extended by numerous researchers in the years since his original work. The spacing effect has been shown to apply to a wide range of materials and learning tasks, including vocabulary learning, motor skill acquisition, and academic learning. It is now widely accepted that spacing out study sessions over time, rather than cramming all the material into a single session, leads to more durable learning and better long-term retention.

The underlying mechanisms of the spacing effect have been the subject of much research and theorizing. One proposed explanation is that spaced repetition allows for more effective encoding and consolidation of the material in long-term memory. When learning is distributed over time, it provides multiple opportunities for the brain to re-encode and strengthen the memory trace, leading to more robust and lasting memories.

Another potential explanation is related to the phenomenon of retrieval practice. When study sessions are spaced apart, learners have to engage in repeated retrieval of the material from memory, which has been shown to enhance long-term retention. Each retrieval attempt serves as a form of practice that reinforces the memory trace, making it easier to retrieve the information in the future.

The implications of the spacing effect for educational practice are significant. It suggests that educators and learners can optimize learning by spacing out study sessions and practice opportunities over time, rather than relying on massed practice or cramming. This has led to the development of various evidence-based study techniques and learning strategies that leverage the spacing effect, such as spaced repetition software and the use of interleaved practice.

In conclusion, Hermann Ebbinghaus's quote reflects his pioneering work on memory and learning, particularly the spacing effect. His research laid the groundwork for our current understanding of the benefits of distributed practice and the impact of repetition on memory retention. The insights from Ebbinghaus's work continue to inform educational practices and have practical implications for how we approach learning and memory enhancement.