Booster card

I think that something like Quantum Country would benefit from having additional cards that you can collect by reading a separate page a month or so after you read the original article. It would cover cards that are less essential but still solidify your understanding -- the stuff in the original article that would have "fallen through the cracks" if you just did the given prompts without re-reading the article. These additional facts might be annoying to collect on a first pass, as you are still trying to make sense of the "main thread" of the article, but become important over time. This might be one escape from Feeling like a perpetual student in a subject due to spaced repetition, and Andy Matuschak's Efficient review scheduling is in tension with gated course sequences.