Information doesn't flow straight from the world into your memory. It has to survive four gates: attention filters what gets noticed at all, emotion filters what's salient enough to matter, cognition can only hold a few things at once, and memory only keeps what gets revisited. Launch some bricks below and watch how few actually make it all the way to the house.
This model maps four well-established cognitive principles onto a simple physical metaphor. None of the four gates work in isolation — what survives attention still has to pass emotion, what survives emotion still competes for limited cognitive capacity, and what cognition holds still has to be revisited before it's truly remembered.
A narrow gate. Most incoming information — regardless of source — never gets through. Unexpected interruptions (notifications) jump ahead of steady, expected input (lesson content), mirroring how a buzzing phone hijacks focus mid-task.
A second, independent filter. Even information that clears attention can still be dropped here unless it carries some emotional salience — curiosity, relevance, or social meaning.
Strictly limited capacity. Working memory can only hold a handful of things at once — anything beyond that is dropped before it ever reaches long-term storage.
Freshly placed information is fragile — it dims and eventually disappears if never revisited. Each recheck, especially spaced further apart over time, makes it stick more permanently.