한 (han). The Wikipedia article quotes Ko Eun saying "We Koreans were born from the womb of Han and brought up in the womb of Han." It's a concept you'll undoubtedly come across if you're interested in Korean literature and history.
Han is frequently translated as sorrow, spite, rancor, regret, resentment or grief, among many other attempts to explain a concept that has no English equivalent. Han is an inherent characteristic of the Korean character and as such finds expression, implied or explicit, in nearly every aspect of Korean life and culture.
Han is sorrow caused by heavy suffering, injustice or persecution, a dull lingering ache in the soul. It is a blend of lifelong sorrow and resentment, neither more powerful than the other. Han is imbued with resignation, bitter acceptance and a grim determination to wait until vengeance can at last be achieved.
Han is passive. It yearns for vengeance, but does not seek it. Han is held close to the heart, hoping and patient but never aggressive. It becomes part of the blood and breath of a person. There is a sense of lamentation and even of reproach toward the destiny that led to such misery. (Wikipedia)