Currently playing on my usual route, ICN -> HKG. The flight path is too ideal. Due to airspace restrictions in china, almost every flight has to divert over taiwan in real life, but this one cuts thru mainland china.

The language barrier between two Korean strangers (irony) is much thicker than when I talk to a passerby in English or Chinese asking for directions.

Typically, throughout middle school to university days, a South Korean individual is expected to use the honorific version of the language when speaking to someone older. This version involves a completely different set of vocabulary and grammar, used to show "respect to others" and sound "polite," effectively preventing one from being casual with others. Whereas a 빠른 is allowed to befriend people one year above their age and gets to use "반말" (the casual version of the language) with those peers.

A social complication can arise when two groups with a monotonic increase in age meet. Say, friend group A comprises a regular 95 and a 빠른 95. They became friends in high school and talk casually. Then there's group B, which consists of a regular 95 and a 빠른 96, who also became friends in high school. Now, when groups A and B start hanging out together at university, the 빠른 95 has to decide whether to use honorific or casual speech with the regular 95 and the 빠른 96.

The ones stuck in the middle, in this case the 빠른95, gets called "족보 브레이커", which roughly translates to "pedigree breaker".

For example, if I'm "빠른95", which indicates that I was born in 1995 between January and the end of February, I get to befriend and hang out with the ones born in 1994.

(Please note that Koreans typically make friends within the same narrow age band.)

In Korean, it works similarly as well though, most people nowadays are quite used to not incorporating Hanja in sentences over multiple decades, to the point where it would be impractical to mingle Hanja in Korean.