grosstalgia 

Memories so gross you'd rather just forget they ever happened

Adjective form : grosstalgic

Nancy : Happy 30th birthday Jim!! Do you remember your birthday 9 years ago when you had 16 shots and threw up all over the club and the bouncers threw us all out?

Jim: That's some heavy grosstalgia

grosstalgia by urbanfervour62 May 20, 2020

ghostalgia

ghostalgia n. (ghost + Gr. algos, pain, grief, distress; cf. nostalgia) Ð a mystical longing or wistful affection for ghosts, angels, miracles, aliens, and other otherworldy characters and mysterious phenomena.

Ghostalgia is a form of nostalgia in that we experience the other world as our genuine lost home.

I am agnostic, but sometimes I feel ghostalgic.

On the eve of deep historical crises, ghostalgia can grip the souls of entire nations.

ghostalgia by Mikhail Epstein November 15, 2003

Groovstalgia 

Groovstalgia is the feeling of finding a song from one of your childhood games (or a remix of it) and enjoying it while remembering your childhood with said game(s).

Yo dude I just found a remix of party ghouls from LBP and its so good it made me have some mad groovstalgia.

Groovstalgia by Darkishappy#2872 February 10, 2021

Ghostalgia

A sentimental longing or wistful affection for a period or place with happy or sad personal associations that has never been experienced before.

-That movie “Dazed and Confused” got me nostalgic
-Dude, you were born in 2000
-Oh, bonkers, I am having a ghostalgia

Ghostalgia by Deepvice June 14, 2022