I've always said my main takeaway from Asimov is that simple rules can generate extremely complex behaviour, and that you can't generally get a targeted complex behaviour from simple rules.

Humans lie to themselves a robot doesn't understand the difference between fact and fiction and thus isnt bound to the limitation. They try everything, possiable or not. And thus will find the edge case where a human would create a self imposed blind spot with out realizing it.

The goal is to midigate the robots attempts at the truely not possible so it doesn't cause harm when they try it.