SuperMemo is based on the insight that there is an ideal moment to practice what you've learned. Practice too soon and you waste your time. Practice too late and you've forgotten the material and have to relearn it. The right time to practice is just at the moment you're about to forget.
During a large disaster, like Hurricane Katrina, warnings get hopelessly jumbled. The truth is that, for warnings to work, it's not enough for them to be delivered. They must also overcome that human tendency to pause; they must trigger a series of effective actions, mobilizing the informal networks that we depend on in a crisis.
Even as the Internet has revived hope of a universal library and Google seems to promise an answer to every query, books have remained a dark region in the universe of information. We want books to be as accessible and searchable as the Web. On the other hand, we still want them to be books.
The problem of forgetting might not torment us so much if we could only convince ourselves that remembering isn't important. Perhaps the things we learn - words, dates, formulas, historical and biographical details - don't really matter. Facts can be looked up. That's what the Internet is for.
Millions of us track ourselves all the time. We step on a scale and record our weight. We balance a checkbook. We count calories. But when the familiar pen-and-paper methods of self-analysis are enhanced by sensors that monitor our behavior automatically, the process of self-tracking becomes both more alluring and more meaningful.
Though social eugenics was discredited long ago, we still often think of the genome in quasi-eugenic terms. When we read about the latest discovery of a link between a gene and a disease, we imagine that we've learned the cause of the disease, and we may even think we'll get a cure by fixing the gene.