"I know it, I just can't remember it..."
This is a genuine quote from one of the students at my school this year - I'll call him Callum.
Having just got a grade 2 in his January mock, Callum was trying to convince me - and probably himself - that he wasn't stupid.
Of course, I never think my students are stupid (they sometimes do and say stupid things, but don't we all?), but it made me think about how we all try and convince ourselves that everything is fine, even in the face of concrete evidence.
So what is the difference between knowing and remembering, and why should we care?
What Callum meant was that he thought that he'd learned the content, but when it came to retrieving it, he couldn't recall it. Like knowing you own that really niche kitchen implement, but not being able to find it when you finally come across a recipe that requires it (I've got quite a few of those...). This suggests that your long term memory is a huge databank waiting to be accessed, and you just need a map to find things, but it is not that simple.
Callum felt like this for a number of reasons:
- the words looked familiar
- he recognised the diagrams
- he remembered the teacher explaining it
- he'd watched a video and it made sense at the time
Whether you think knowing and remembering are very different, it doesn't really matter when you're studying for your GCSEs. In the exam, only what you remember and recall can score you marks.
Callum felt like he ‘knew’ the content because several things gave him a false sense of familiarity. His revision strategies probably focused on passive strategies, but with no retrieval practice, like:
- rereading notes
- highlighting
- watching videos without testing themselves
- “going over” a topic instead of practising it
These methods build familiarity, not memory. They make students feel prepared while leaving retrieval strength untouched. And when the mock arrives, the brain goes blank - not because the knowledge isn’t there, but because the student never trained themselves to access it.
And now the fix. Callum needed to use revision strategies that required him to think hard and practise retrieving information without any memory aids in front of him. Strategies like:
- Active recall: answering questions without notes
- Spaced repetition: revisiting topics over time
- Interleaving: mixing topics so the brain has to choose between ideas
- Low‑stakes testing: frequent quizzing, not occasional cramming
- Desirable difficulty: making practice intentionally challenging
These methods feel harder, and that’s why they work.
So as you start to build your revision routines, make sure you are using the right strategies. It isn't always the hardest working students who score the top marks, it's the ones who worked smartest.
The Nebula Learning Lab naturally supports the shift from familiarity to retrieval with a range of strategies:
- Short videos → build initial understanding
- Key notes → strengthen encoding
- Question banks → train retrieval
- Rewatching tricky parts → reinforce weak links
- Diagnostic quizzes → expose retrieval gaps early
- Exam questions → practise application of knowledge, turning knowledge to marks.