Murphy’s Law (Why do we believe that anything that can go wrong will go wrong?)
Murphy’s law, a brief explanation
What is the Murphy’s Law?
Murphy’s law is the tendency to believe that anything that can go wrong will go wrong.

Examples
On a long journey to holiday with your family in a full car you develop engine problems and the car breaks down.
Whilst having breakfast you drop your toast and it lands jam-side down.
The literature
Matthews, R. A. J. (1997). The science of Murphy’s law. Scientific American, 276(4), 88-91.