Wikipedia says:
The term nostalgia describes a longing for the past, often in
idealized form.
[1] The word is a learned formation of a Greek compound, consisting of (νόστος nostos "returning home", and άλγος algos "pain"). It was described as a medical condition, a form of
melancholy, in the
Early Modern period, and came to be an important topic in
Romanticism.
[1] True nostalgia is an ephemeral composition of disjointed memories. - Florence King
There's a certain nostalgia and romance in a place you left. - David Guterson