When firing up Apache the other day, XAMPP presented me with the ever helpful error message:

Taking a step back, Wikipedia describes error messages as:
a message displayed when an unexpected condition occurs, usually on a computer or other device. Error messages are often displayed using dialog boxes. Error messages are used when user intervention is required, indicate that a desired operation …

“Aha!”, they say, “We can handle mouse events and return false!” This is completely wrong. To me, one of the most important features of software development is usability. You can have the most sleek design, the most killer algorithm, but with a poor user interface and workflow, these become irrelevant.