Your comment got me thinking about what it really means to understand something. Is it just about remembering the facts or the ideas? Or is it more about being aware of them? I’ve watched a ton of YouTube videos and read a bunch of articles about physics, but I can’t remember how to derive those equations a few weeks later. So, I don’t feel like I really understand them. But if I have an idea about how to do it, how much of it is just memory, and how much is actually understanding the concept? That’s been a question I’ve been thinking about for a long time. With all the AI stuff, we’ve figured out how to deal with the memory part, so we don’t have to rely on our own memories as much. But that still leaves the question: what does understanding really mean?

I've thought about this a lot in the context of "why do I need to learn facts when I can just look them up?"

Understanding a concept means you are able to use it in higher order reasoning. Think about the rote practice necessary to build intuition in mathematics until you're able to use the concept being learned for the next concept which in turn relies on it.

Once that intuition is built, that's understanding.