kleptoamnesia 

Kleptoamnesia is a psychological disorder in which people steal things without any memory of the theft. This can cause much confusion and make the client the perfect thief.

Every time I go out with my aunt she commits small thefts because of her kleptoamnesia. Her disorder makes it really awkward when we go to the mall.

kleptoamnesia by house505 December 5, 2017

kleptonesia 

(n.) condition characterized by forgetting the source of a stolen idea

His paper borrowed heavily from classical and contemporary sources, but his kleptonesia prevented him from giving credit where it was due.

kleptonesia by futuretense June 16, 2009