To be thrown is not a question of time. "Falling" does. For Heidegger, falling means falling from the past as well as falling from the future.
By losing his hold on the past and the future, man will start to drift into a life that is devoid of direction and meaning, but is filled with disillusionment, anxiety, and restlessness. This is what Heidegger meant when he claims that man has a fallen nature. Man, sooner or later, will lose his individuality and disappears into the same herd that was much detested by Nietzsche.
If man has to search for his authentic existence, he has to retrieve his primeval and originary concern from his forgotten past. But such retrieval will only start to happen when man comes face to face with the idea of his own death as his ultimately real possibility. An authentic contemplation of his own death will forcefully remind him of his own individuality and the finiteness of his existence. This shock will make him retrieve his original concern and move on with his futuristic projection.
If redemption has a backward movement for Plato, and a forward movement for Kierkegaard, it has a circular movement for Heidegger. Here, redemption means Wiederholung, or retrieval, of the past's futuristic concern.
