Nostalgia

The term nostalgia describes a sentimentality for the past, typically for a period or place with happy personal associations. The word is a learned formation of a Greek compound, consisting of νόστος (nóstos), meaning “homecoming”, a Homeric word, and ἄλγος (álgos), meaning “pain, ache”, and was coined by a 17th century medical student to describe the anxieties displayed by Swiss mercenaries fighting away from home.