Knowing what is in the model is a long way from understanding it.
The entire field of mechanistic interpretability exists to try to understand models. Read for example "Open Problems in Mechanistic Interpretability"[1]. To quote:
> Developers only need to design the training process; they do not need to – and in almost all cases, do not – understand the neural mechanisms underlying the capabilities learned by an AI system.[1]
(emphasis mine)
Here's a practical example relevant to this case: Is it possible to monitor a LLM (the LLM activations themselves, not the actions) for cases where the actions it is about to perform (eg upload files to a PLA website) are not reflected in the goals of the prompt and are not visible in the thinking trace?
At the moment that isn't possible. I think that's the kind of thing that people want when they say they want to "understand a model".