It means that if I pick up a random USB cable and plug it into a USB port I have no idea how well it will work or even if it will work at all. It's like the U in USB stands for Unpredictable.
An even more general problem is that we as humans use pattern-matching as a cerebral tool to navigate our environment, and sometimes the patterns aren't what they appear to be. The Norway problem is the programming equivalent of an optical illusion.