Could be memories of past lives.
The laughing Cherub Guide to Past-Life Regression: A Handbook for Real People, written by therapist Mary Elizabeth Raines, tells about her accidentally learning to cure patients with persistent problems by healing memories from their past lives, and gives instructions on how to do this for yourself at home.

I'd had certain troubling phobias and problems all my life, and never could cure myself that vanished instantly when I revisited the appropriate past life where the trauma first occurred, and re-imagined the traumatic scenes as being happy events instead, where the bad stuff never happened.

Turned out, I didn't have to go through her complicated processes-just tell myself to return to the past life where the trauma first occurred, then just "imagine" it. To my shock, I remembered the past lives vividly, and even verified some details by googling incidents. I visited a number of past lives to hit a number of problem areas.

The relief was so profound, I didn't care whether or not the imaginary experiences were "real," as long as they worked.

It might be in the dictionary of obscure sorrows:

[dictionaryofobscuresorrows.com]

Day dreaming

I reckon its that feeling that makes you smile and sigh at the same time, I wonder if it does have a name tho

Yearning? I don't know, deprived?

Daydream Believer. Or, a different, special kind of daja vu perhaps??

The word is 'loss'.

kind of a synesthesia with time, I often have this feeling and the only way to describe it is it is like music that has no noise.AND no I do not do drugs, I am lucid for those that think this is an explanation.

Fernweh.

It is called American history as it is taught in our schools.

Here is something to which you might relate

Miniver Cheevy, child of scorn,
Grew lean while he assailed the seasons;
He wept that he was ever born,
And he had reasons.

Miniver loved the days of old
When swords were bright and steeds were prancing;
The vision of a warrior bold
Would set him dancing.

Miniver sighed for what was not,
And dreamed, and rested from his labors;
He dreamed of Thebes and Camelot,
And Priam’s neighbors.

Miniver mourned the ripe renown
That made so many a name so fragrant;
He mourned Romance, now on the town,
And Art, a vagrant.

Miniver loved the Medici,
Albeit he had never seen one;
He would have sinned incessantly
Could he have been one.

Miniver cursed the commonplace
And eyed a khaki suit with loathing;
He missed the mediæval grace
Of iron clothing.

Miniver scorned the gold he sought,
But sore annoyed was he without it;
Miniver thought, and thought, and thought,
And thought about it.

Miniver Cheevy, born too late,
Scratched his head and kept on thinking;
Miniver coughed, and called it fate,
And kept on drinking.

n/a​

No I live in the present.

That is a very interesting question. I collect words, especially the very specific one like the one you are looking for. In German ,we have a word Heimweh, homesickness, that is made up of two words, heim=home and weh= ache or pain. This word , Heimweh , has been expanded to Fernweh= the ache for places far away, and now to Meerweh.the ache or desire for the sea.
I do not know if we could come up with a term , in German, that would describe the ache for an ubnknown place or situation. I'll be following this thread. it is very interesting.

Heartsick.

Deja vu?

hiraeth is a longing for a place you have never been or doesnt exist. it is as close as i could think of

Imagination.