You only know something when you can recall it.
There are three stages for memory:
- Intake - when you experience something.
- Storage - when your brain stores that information.
- Recall - when you try to retrieve a stored memory.
Imagine a library. Intake is when the library orders a new book. Storage is when the library shelves it. But if you can't find the book, it's useless.
Recall is why a skill seems easy during a lesson, but difficult when you try it on your own. The lesson didn't ask your brain to retrieve anything.