I commend the author's discipline - this is a pretty standard approach. TLDR - Move as many things as possible in regular life to the target language (software, tv shows, reading, etc) to maintain the language - There is no substitute for full immersion if you have the opportunity. I learned traditional Chinese in Taiwan while I was an ESL teacher. - The power of SRS (spaced repetition system) cannot be overstated I…
Speaking as someone who has used Anki the last 5 years, has built and sold Anki decks and is working on implementing various spaced repetition schedulers as we speak... unfortunately its importance can absolutely be overstated.
Definitely more language learners should be using an SRS, but there are lots of people who take it way too far (I have way too many stories).
Where things go wrong for most people is their understanding of the role of the SRS. The SRS to language learning is what protein shakes are to bodybuilding. But while no serious body builder would try to get ripped by drinking protein shakes and neglecting working out, there are unfortunately tons of language learners doing basically just that with the SRS. To acquire a language you need input! The SRS is just (very) helpful supplement.