Spaced repetition is not about memorization
Spaced repetition isn't about memorization: this is somewhat of a clickbait title. It's more accurate to say "Spaced repetition isn't just about memorization, or even primarily about memorization". Of course spaced repetition involves memorizing things, but for me the interesting parts are about learning how my mind works, how to explain concepts better (e.g. better modeling how your reader's minds and attention work), and how to build an engaging way of learning.
I think something like Tao Analysis Flashcards can be extremely fun to consume -- way more fun than playing Braid. And understanding how that "funness" is created is more important than actually making sure people retain all of what they've learned in real analysis.