The forgetting curve, one day at a time
A new word is already fuzzy by bedtime. The useful fact is not that you forget — it is that each successful review slows the next fade. After the first recall you get days. After the next, weeks. Cramming two hours on Sunday still works the night before a test. It almost never works in a conversation a month later. Example: you meet 눈치 on Monday. Before sleep, cover the gloss and say it once — the feeling of knowing when to stay quiet, not a dictionary line. Thursday, if it will not come, pull the next review closer. If it jumps out, skip ahead a week. Write “Mon / Thu / the Monday after next” on a calendar. That is your interval. No algorithm required. People treat a forgotten word as proof they are bad at languages. It is usually proof the gap was too wide. Stretch what comes easily. Shorten what dies. The curve is personal, and it only shows up if you actually try to retrieve the word instead of admiring the list.
An interval you can keep: same day → 3 days → 1 week → 1 month
A rule you will follow beats a formula you abandon. New expressions: tonight, three days later, one week later, one month later. Instant recall → stretch. Blank → pull forward. That is the whole policy. A 12-minute day that survives a job: • 3 minutes before leaving: five cards from yesterday, meaning covered, spoken aloud • 4 minutes at lunch: turn the two you missed into sentences — 눈치 없다 about a real coworker, not a textbook nobody • 5 minutes in bed: three new items + three from three days ago If “today’s pile” passes ten cards, it has become homework. Keep the misses. Push the rest. Deleting a wrong card feels tidy and throws away the most expensive signal you have: this one is not yours yet.
Do not reread. Retrieve.
Scanning a list again is not review. It is rewatching. Cover the meaning and produce the word, or cover the word and produce the meaning. Struggle is the point. A miss is a stronger mark than a fluent glance. Failure case: the commute app, swipe, “yeah I know this,” next. A week later in a café the same word dissolves in your mouth. The feeling of knowing and the ability to pull a word out are different memories. Recognition is cheap. Production is the one you need when someone is waiting. A small fix: three seconds with your eyes closed before you look. On a bus, mouth the shape. Silent retrieval still counts. If you cannot say it without the card, it is not reviewed — it is decorated.
A five-minute shape that does not require a system
The enemy of spaced repetition is the grand setup. “I’ll build a system first” usually means you will not start. If you already have a list, fold the paper or hide the gloss. A timer for five minutes is enough. A game is fine if it asks you to produce, not to tap yes. When you miss a day, do not repay the debt. Do today’s date only. Aim at a weekly count — five days, not a sacred streak. An empty Tuesday should not kill the month. Sunday night check: how many cards did you actually flip without peeking? If the number is zero and you “studied” for an hour, you studied the feeling of studying. Flip five before you sleep and the week still happened.
COMMON MISTAKES
Where spaced repetition quietly fails
Cramming like exam eve — scores rise, the month erases them. Skimming and trusting the “I know this” glow — unused memory does not strengthen. Deleting misses — those are the ones that need a shorter gap. Adding twenty new words every day — the review queue explodes and people close the list. Three to five new items travel further. Shopping for the perfect app for a week — five cards tonight beat any download.
If you already have a handful of words, flip five before sleep. Tonight’s routine is then finished. A quiz screen is handy if you have one; a folded scrap of paper is the same motion.