> Why does that keep happening?

A human has painful memories of past mistakes and knows which of their own thinking process needs to be double checked and which can be accepted on faith. An llm has no such memory, it can either verify every single word or none of them. And verification itself needs to be verified. So they have to stop somewhere.

This is why llm usually produce text that’s too shallow or too detailed.

When you ask the agent to double check something you gave it the missing piece - intuition about which part needs to be checked.