[paytonjjones]

I feel like...that's terrible advice?

Voluntary retrieval (the memory "mode" of flashcards), even for simple pairs, is perceived as highly effortful by almost everyone, on a similar tier to doing mental math.

It's incredibly efficient for learning, and achieving your goals quickly can be very rewarding, but I don't think "learning flashcards should be fun!" is a reasonable expectation for the vast majority of people.

[iamanllm]

Most people don't use flash cards at all. So if their experience with them is terrible then why would they keep doing it? Also effort can be fun. Working out is effortful and most people don't do it. So, they should go to the gym and try to have a good time. If they aren't, maybe the advice to do some 5x5 program or Jocko whatever workout is not good for them. It's just a heuristic to stay motivated. But yeah, my friend just finished med school and memorized like 30k extremely complicated cards. He did not "have fun".

[rsanek]

It's a balance. Maybe a helpful analogy would be a book -- yes, reading a book is effortful, and yes, "almost everyone" does not read. Still, I think most wouldn't consider it crazy to say that reading can be "fun."