APAD: three times is a pattern

The full expression of the phrase as "Once is an accident, twice is a coincidence, three times is a pattern". This adage suggests that a single occurrence is a random accident, two occurrences might be a coincidence, but three occurrences indicate a clear pattern or trend, often signaling an underlying issue needing attention. It is a common rule of thumb for identifying, analyzing, and addressing recurring behavioral or data issues. It signifies that repeating an action or event three times indicates a non-random, underlying system, issue, or trend. 

 Often attributed to author Ian Fleming, who wrote in Goldfinger, "Once is happenstance. Twice is coincidence. Three times is enemy action". 

In businesses, it used to indicate that a recurring error or user complaint suggests a necessary process change or a bug.  It suggests that repeating a behavior indicates a conscious choice or established habit rather than a mistake. It serves as a rule of thumb to stop ignoring repeated, problematic events and start addressing them.