A type of mental illness
In 17th century, Swiss soldiers were serving abroad because of the war leaving their hometowns. They seriously missed their hometowns spending a long time away from home. There were even physical symptoms such as eating disorder, sleeplessness that showed to some of them. At that time, Johannes Hofer a medical student who was studying about such disease, created the word 'nostalgia' combining two Ancient Greek Nostos(homecoming) and Algos(pain).
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