Retention

Of course, acquiring knowledge is just the beginning. Retention—keeping that knowledge over time—is where real progress happens. Cognitive science tells us that the key to retention is the spacing effect (thank you, Ebbinghaus). At scintilla.ai, we’ve spent years figuring out how to optimize that effect and prevent forgetting.

Here’s the trick: the most effective time to revisit a topic might be four months after you first learned it. Our AI knows that. But AI alone can’t motivate you to return—that’s where great game design comes in. MMORPGs keep players coming back for months, even years.

In The Hundred, maybe your sand-pile dragon hasn’t been used in a while. A new beast has appeared—and to defeat it, you need both your dragon and a quick refresher on longshore drift. Finally, the moment has come: you answer a few questions, crush your opponent, and earn a rare piece of epic armor. Oh, and by the way, you’ve just given your memory a strength boost of 5–20×. Not bad for a revision session.