"Oedipus Rex" by Sophocles

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…after committing awful crimes in your life are all the things that Oedipus sees after his misconception of his entire life is destroyed and he sees the things he could have prevented. When you look back on your life and see something that brought about bad consequences you most often see how you could have easily avoided the usually small detail that caused the whole ordeal. that is usually a great learning experience for you.