Both oil producers and miners recall painful lessons of previous decades when low prices were the norm.

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Banks are highly regulated and have learned some painful lessons over the years.

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One of the more painful lessons all investors learn is that a 20%-40% loser in your portfolio can offset the nice gains from the other holdings.

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The markets teach us all painful lessons.

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If a company launches its efforts too soon, it may suffer unnecessarily through the painful and expensive lessons associated with deploying an immature technology.

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Winfrey also guided us through the painful experience and lessons learned when her Leadership Academy faced a distressing, and highly publicized crisis in 2006.

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As for the news business, the lessons have been painful.

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