The word "刚刚" is formed through a common Chinese morphological process called reduplication, where the base character "刚" (meaning "just" or "exactly") is simply repeated. This duplication does not create a new, separate concept but instead intensifies and softens the original meaning, adding a sense of immediacy and recent completion to the notion of "just now". The formation is purely structural, relying on the rhythmic and emphatic power of repetition to modify and nuance the core idea carried by the single character.