In Chinese culture, the relationship between the private sphere (`私人`) and the public sphere (`公共` - gōnggòng, or `公` - gōng) is a fascinating and evolving concept. Traditionally, collectivism and family were paramount, and the Western idea of strong individual privacy was less emphasized. The character `私` could even carry a negative connotation of being selfish (`自私` - zìsī). The group's needs, whether the family or the state, often came before the individual's. However, in modern China, especially with rapid urbanization and the influence of the internet, the concept of `私人` has become much closer to the Western understanding of “private.” People increasingly value their personal space, data privacy, and private life. It's now completely normal and acceptable to say “This is a private matter” (`这是我的私事`) to set a boundary, something that might have been considered standoffish in a more traditional context. The key difference to a Westerner is the source and boundary of this privacy. While in the West, privacy is often seen as an inherent individual right against all others (including the state), in China, the lines can be more fluid. Privacy is often strongly asserted among strangers and acquaintances, but expectations might be different within the family or when dealing with government or community matters. The tension between `公` (public/collective good) and `私` (private/individual interest) is a central theme in Chinese society.
`私人` is an extremely common and practical word used in a wide range of situations.