Murphy's Law / Sod's Law
Anything that can go wrong will go wrong.
Related to Edward A. Murphy, Jr Murphy's Law states that if a thing can go wrong, it will go wrong.
This is a common adage among developers. Sometimes the unexpected happens when developing, testing or even in production. This can also be related to the (more common in British English) Sod's Law:
If something can go wrong, it will, at the worst possible time.
These 'laws' are generally used in a comic sense. However, phenomena such as Confirmation Bias and Selection Bias can lead people to perhaps over-emphasise these laws (the majority of times when things work, they go unnoticed, failures however are more noticeable and draw more discussion).
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