Continuity mistake: When Carol, the MLI employee, is first seen carrying the white bucket in the corridor and also when Carol thinks she located Hank, the bucket has absolutely no writing on it where the handle's attached on both sides, but when Dory looks down at the bucket suddenly "Destiny" is written on it.
Chosen answer: In the absence of a neuropsychological work-up, we have only Dory's word for it: "I have short term memory loss...It runs in my family...at least, I think it does." So, Dory believes it to be genetic. At least, I think she does.
Michael Albert