User Error Isn’t
It happens to every developer at some point. You spend a bunch of time trying to determine the source of an urgent bug, only to find out the problem was caused by action or inaction of the user. It’s easy in that moment to be frustrated, but may I suggest a more circumspect path? It behooves a thoughtful developer in these moments to consider if the source of the user error was caused by poor design. Perhaps the button wasn’t in an obvious place, or the side effects of the command were not obvious, or the name of the feature didn’t describe the outcome. In many (even most) cases, user error is preventable with good design.
Yes it’s difficult, and perhaps impossible in some situations. But it is the high calling of the software engineer to design products in a way that a user almost subconsciously knows how to operate without error. Viewing design with this attitude saves a lot of frustration.
It might seem this is a counter argument to Not Even Mostly, but actually they go hand in hand. A user must be carefully listened to and considered, but sometimes they must also be guided into the features they really need, versus what they say they want. Do that hard work up front, and you’re more likely to have a system that minimizes the potential for mistakes.
Also, go read The Design Of Everyday Things.