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to forget completely; to leave behind
辛い経験も時間が経てば忘れ去った。
Even painful experiences were forgotten completely with time.
かつての夢を忘れ去っていることに気づいた。
I realized I had completely forgotten my former dream.
人はつらい記憶を忘れ去ることで生きていける。
People can go on living by completely forgetting painful memories.