Memory Curve · 记忆曲线
Never forget
what you learned.
We use the SM-2 spaced-repetition algorithmto schedule each card's next review at the exact moment before you'd forget it. Email reminders bring you back without nagging. Optional AI-managed Discord group for the social-motivation boost.
The problem
You forget 75% of what you learn — in 6 days.
That's the Ebbinghaus forgetting curve (1885), confirmed by every modern learning study since. Without scheduled review, by the time May exams arrive you've quietly lost most of November's material.
- Re-reading notes does not fix this — it feels familiar but you can't recall.
- “Mass cramming” the week before the exam works for 24 h then craters.
- What works: review just before you forget. Hard to do by hand.
Without review — Ebbinghaus curve
Memory drops fast — the steepest loss happens in the first 24 hours.
The fix
Show me the card right before I'd forget it.
Each time you answer a practice question, we tag it with how hard it felt. The SM-2 algorithm (used by Anki, SuperMemo) computes the optimal next review date — usually 1, 3, 7, 16, 35, 80 days out, doubling as you master it.
Day 1
first encounter
Day 3
rough recall
Day 7
getting easier
Day 16
reliable
Day 35
long-term
Day 80
permanent
(Intervals shorten if you mark a card “hard”; lengthen if “easy.” Fully adaptive to your memory.)
How it works
Practice
Answer a MCQ, FRQ, or concept card. After grading, rate how hard it felt: Again / Hard / Good / Easy.
Algorithm schedules
SM-2 computes the next-review date based on your rating + this card's history. Stored as a memory-curve card per topic.
You get reminded
Dashboard shows "X cards due today". Email digests Mon/Wed/Fri. Optional Discord ping. You re-test in 60 seconds.
Email reminders
We email you exactly when reviews are due — never more.
One digest, three days a week. Skip a day? The next email picks up where you left off — no scolding, no streak shaming.
- Schedule — Mon / Wed / Fri at 7 PM your timezone
- Frequency cap — Never more than 3 emails / week
- Personalized — Shows your top 3 weakest topics + 1-click resume link
- Quiet mode — Toggle off anytime in Settings; spaced review still works
5 cards are due — about 6 minutes of review
Wednesday · 7:02 PM
AP Calculus BC
L'Hôpital's rule · indeterminate forms
CSCA Math
Trigonometric identities · sum/diff
AP Physics 1
Free-body diagrams · friction
Unsubscribe · Manage frequency
Annie 7:14 PM
Stuck on the 2024 FRQ #3 part c — anyone? 😭
Borui Academy Tutor BOT 7:14 PM
That problem expects the chain rule + implicit diff. Try this:
1. dy/dx from the implicit relation…
2. plug in x = 1, y = 2…
Want me to walk through step 3?
Marcus 7:16 PM
just solved this one yesterday — yeah it's ch3 trick
AI-managed Discord
Coming soonAn always-on study group + an AI tutor that never sleeps.
Join the Discord server for your subject. Per-channel AI tutor bot answers questions 24/7, cites the chapter, and pulls in the exact past-paper context. Real students chime in too.
- AI tutor — GPT-class model fine-tuned on the chapter content + past papers
- Peer cohorts — Bucketed by subject + exam date — find people on your timeline
- Daily rituals — Bot pings the channel with one daily warm-up + weekly mock results
- Moderated — AI auto-removes spam / chat heroics; human mods for tone
Free for all members during launch. Premium-only after general release.
The science
Not a productivity hack. It's well-established cognitive science.
Spaced repetition is one of the most replicated findings in learning research — from Hermann Ebbinghaus (1885) to Bjork's “desirable difficulty” (1994) to the SM-2 algorithm (Wozniak, 1987) that powers Anki and SuperMemo. We adapted SM-2 to grade per-question cards inside each course, with email + Discord nudges layered on top.
Lock it in, the smart way.
Try the memory curve free on any course. 7-day trial for full features.