gamnesia 

the loss of memory of events that occurred during the relationship after the relationship has ended.

Did I say that, I don't remember doing that with you. I never said or did such a thing. (but I could have gamnesia).

gamnesia by tydwell July 25, 2006

glamnesia 

The condition in which a person acts in complete disregard of their status of glam.

David Bowie had a major case of glamnesia when he admitted to being a closet heterosexual.

glamnesia by Simon Lexington January 29, 2008

Gramnesia

When you become a grandparent and forget how you raised your own children.

“Wow mom really had gramnesia when she let the kids have ice cream before dinner!”

Gramnesia by Dogmom000 May 25, 2021

gamenesia 

The act of returning to a game you haven't played in an extended period of time and having completely forgotten how to play, how your abilities work, what you're supposed to be doing. or all of the above.

Person 1: Man, it has been so long since I last played World of Warcraft that I have no idea what I'm doing.

Person 2: sounds like you've got a case of gamenesia.

gamenesia by chaosweapon1 December 7, 2015

Gymnesia 

When you have not been to the gym for an extended period of time due to laziness or any other poor excuse.

Donnie: Where you been homey, I haven't seen you in ages?
Greg : All this partying is really taking its toll. I have severe gymnesia!

Gymnesia by Gregsands August 22, 2012

Gymnesia 

A habitual or compulsive involvement in physical exercise in a gym or fitness centre that leads to the detriment of other aspects of the individual's day to day life.

I haven't seen Billy for a while. Where's he got to?
That guy's got a bad case of Gymnesia!

Gymnesia by BijomaruMogami September 1, 2017