You can indeed tell if something is true or untrue. You might be wrong, but that is quite different -- you can have internal knowledge that is right or wrong. The very word "misremembered" implies that you did (or even could) know it properly.

LLMs do not retain facts and they can and frequently do get information wrong.

Here's a good test. Choose a video game or TV show you know really well -- something a little older and somewhat complicated. Ask ChatGPT about specific plot points in the video game.

As an example, I know Final Fantasy 14 extremely well and have played it a long time. ChatGPT will confidently state facts about the game that are entirely and totally incorrect: it confuses characters, it moves plot points around. This is because it chooses what is likely to say, not what is actually correct. Indeed, it has no ability to know what is correct at all.

AI is not a simulation of human neural networks. It uses the concept of mathematical neural networks, but it is a word model, nothing more.