Dementia Patient 

Someone who forgets too much.

Jason: Hey what time does the game start?
Jack: Ummmm.... I forgot
Jason: Wow jack you're a real Dementia Patient
Jack: I know :(

Dementia Patient by Obligitory Pseudonym October 21, 2019

Dementia patient 

Sleepy Joe Biden

Sleepy Joe Biden: the rapidly rising uh, um with uh um, in with uh, with uh, I don't know who, anyway...

Joe Biden is a real dementia patient

Dementia patient by Cornpop was a bad dude July 25, 2022