This is not about understanding the message, but switching user mental activity.
I go myself in the similar situations many times. One example: I tried to pay my bills in online bank application, but got into error. After several attempts, I did read message and it say "Header size exceed..." . It give me clue that app probably put too much history into cookies. Clear browser data, log in again, and all got works.
Even when error message was clearly understandable for my expertise, it took surprisingly long tome to switch from one mental activity - "Pay bills", to another - "Investigate technical problem". And you have to throw away all short memory to switch into another task. So all rumors about "stupid" users is direct consequence from how human mind works.
> This is not about understanding the message, ...
99% of the population have no idea what "Header size exceeded" means, so it absolutely is about understanding the message, if the devs expect people to read the error.
Yeah, I would certainly not expect the user to understand what to do about a "Header size exceeded" error.
But I WOULD expect the user, when sending a message to support, to say they're getting a "Header size exceeded" error, rather than just say "an error".
Even when error message was clearly understandable for my expertise, it took surprisingly long tome to switch from one mental activity - "Pay bills", to another - "Investigate technical problem". And you have to throw away all short memory to switch into another task. So all rumors about "stupid" users is direct consequence from how human mind works.