Besides directly strengthening a memory, what INDIRECT benefits does retrieval practice have?

It makes any later re-study more effective, and it reveals exactly where your gaps are so you can target them.

Two mediated (indirect) benefits:

1. Better re-study. After a test, going back over the material lands harder — you now know what mattered and where you struggled, so re-reading is no longer undirected.
2. Better metacognition. A failed retrieval is honest feedback: it exposes a gap that re-reading would have hidden behind a comfortable feeling of familiarity. This improves your calibration — how well your confidence matches your actual knowledge.

So retrieval both teaches and diagnoses in one step.