The QA Engineer's Nightmare

The perfect encapsulation of QA testing versus real-world usage. The QA engineer dutifully tries every imaginable edge case - normal input, zero input, integer overflow, negative values, and even random gibberish. Everything passes with flying colors!

Then some innocent user walks in and asks the most basic, completely reasonable question that nobody thought to test... and the entire system implodes spectacularly.

It's the software development equivalent of building an impenetrable fortress with laser turrets, shark moats, and retinal scanners... only to have someone walk in through the unlocked back door.