It's a part of the what human mind is dependant upon, but when is it taken so far it should be seen as a mental disorder?
That's a good way of putting it or ignorant to the future advances. many words could be for it obsession is one
When you cant let go of the past and try to stay there as much as possible Basically every day I live is unhealthy.
I'm pretty sure I'm on the unhealthy side of nostalgia. I legitimately long for days past, even to a point where I want to live in a time and place I have never experienced. I spend a lot of my time researching and looking into things I draw a nostalgic/personal connection to as well. It's easier to take comfort in an established past rather than an uncertain future. It's also easier to get caught up in the past with a wealth of media from a collective and defined time period being there for one's enjoyment online.
Agreed, it's just like with anything in life really; it's unhealthy as soon as it stops you from doing necessary things.
personal history only tends to remember the good things, the 90's kinda sucked for most people but there are things that are comforting. Not having the constant tether of the internet, bringing you down, discussions flowed more naturally and young people could actually form a conversation face to face (say in a store with a clerk)
It becomes unhealthy when you keep thinking about the past to the point where it drains and depresses you, and/or you keep trying to relive it. If thinking about the past is violently changing the way you act in the present, there's a problem.