When I'm working on a problem, I can explicitly apply knowledge I gained decades ago to that problem. Not just "oh, it's somehow encoded in the training data"; not "oh, it's all mixed in there somewhere"; I can call up the memories, understand how to apply that knowledge to the problem at hand, and do so.
Except in certain very superficial ways, and despite many misguided LLM proponents' strident insistence to the contrary, LLMs do not work much like human brains.