Kurtz must have had some inkling about the boundaries he had crossed and the taboos he had broken in order to make such a statement concerning the snail and the razor's edge.
One of the psychological confusions contributing to PTSD is the 'survivors guilt' angle, and the knowledge of what one must go through to survive.
Another interesting angle, one that Kurtz obviously knew a little too well, is the emergence of one's inner 'berserker,' something that is also well-covered in Norse myth, myth that clearly grew out of ancient peoples observations of the world.
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Kilgore, with his seeming immunity to bullets, also displays some of the berserker qualities, fancifully described as a 'radiance'
Willard: [about Colonel Kilgore] Well, he wasn't a bad officer, I guess. He loved his boys, and he felt safe with 'em. He was just one of those guys with that weird light around him. He just knew he wasn't gonna get so much as a scratch here.[
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