The Chinese idiom "不知不觉" is formed through a classical parallel structure, combining two nearly identical verb phrases: "不知" (bù zhī), meaning "not know," and "不觉" (bù jué), meaning "not feel" or "not perceive." This four-character pattern, common in fixed expressions, uses repetition and parallelism for emphasis, where the two halves reinforce each other to create a single, cohesive meaning. Literally describing a state of being without knowledge or sensation of a process, it figuratively conveys the idea of something happening gradually, subtly, or unconsciously, without one's awareness.