I think it would be really interesting to apply the component failure system resilience design principles to education: high availability systems are designed on the assumption that hardware components fail, but that when a failure occurs the system continues to operate.
Similarly, educational programmes should be designed on the basis that the learner will forget, and as such, the mechanisms for dealing with a "forget" scenario.
Fundamentally, all there should be an expectation that all educational materials used by a learner are available to that learner for the rest of their life, creating a "non-brain memory". This is all the more possible now that learning materials can be stored electronically.
The key is that learners learn to add to, reference from and refine their non-brain memory. Ensuring learners have a well organised set of non-brain memory should be of upmost importance to educators.
There are numerous techniques to increase the usefulness of non-brain memory. Obviously, the search functionality of electronic media is ideal for allowing a learner to find information relevant to the topic they need to refresh. But there are also techniques such as creating topic summaries or cheatsheets that provide rapid access.