The author considers the medical rationale for Wilhelm Fliess's operation on Emma Eckstein's nose in February 1895 and interprets the possible role that this played in Freud's dream of Irma's injection five months later. The author's main argument is that Emma likely endured female castration as a child and that she therefore experienced the surgery to her nose in 1895 as a retraumatization of her childhood trauma. The author further argues that Freud's unconscious identification with Emma, which broke through in his dream of Irma's injection with resistances and apotropaic defenses, served to accentuate his own “masculine protest”. The understanding brought to light by the present interpretation of Freud's Irma dream, when coupled with our previous knowledge of Freud, allows us to better grasp the unconscious logic and origins of psychoanalysis itself.1