The aim of the current work is to introduce the phenomenological idea of traumatic retroactivity with the help of Freud’s retroactive trauma theory that relies on the afterwardsness of trauma (Nacthräglichkeit) and incorporates progressive and retrospective movements in time. To accomplish this task, the paper examines the Freudian problem of afterwardsness of trauma and its phenomenological interpretations, then it suggests that Freud’s idea can be re-interpreted or re-modeled phenomenologically as a form of affective retroactive awakening of the past. In addition, the paper differentiates between retrospective narrative thinking and retroactive affective awakening. The former is a way of self-understanding and can be identified with the retrospective side of afterwardsness, whereas the latter is closely related to the affective awakening of the past and denotes the progressive side of retroactive trauma. The two phenomena are regarded as two intertwined aspects of traumatic retroactivity. Finally, the paper proposes that the retrospectively understood memory traces, on which retroactive trauma was based, could be explained by the phenomenological unconscious, more precisely, by the notion of the affective past-horizon.