Spaced repetition is a technique for exploiting psychology's spacing effect for getting information to be stored longer [1]. That is (roughly) a memory needs to be recalled to be retained and the optimal time to do that recall is just before forgetting the material. This is implemented by Anki, which I loved using throughout my PhD and a few years afterwards with 20K+ flash cards on AI, math, and neuroscience. I started skipping doing it every day after becoming a professor, but I wish I had the time to pick it back up.

Also, memories become plastic and maleable when recalled, so just because they can recall something does not mean the memory hasn't been twisted by doing so [2].

[1] https://en.m.wikipedia.org/wiki/Spacing_effect

[2] https://en.m.wikipedia.org/wiki/Memory_consolidation (see section on reconsolidation)