[Freud] goes on to cite a technique which is useful to the psychoanalyst but, in addition, we could say, to anyone, for shedding light on what has been repressed in a given situation.
"What would you consider the most unlikely imaginable thing in that situation?
"What do you think was furthest from your mind at that time?"
If the patient, or whomever you happen to be talking to at a party or over dinner, lets himself fall into your trap and tells you what he considers to be the most unbelievable thing, then that is what you have to believe.
from "A Spoken Commentary on Freud's 'Verneinung' by Jean Hyppolite," an appendix to Lacan's Écrits (emphasis supplied)