"Because of the unfortunate stigma that still exists in the United States around homosexuality ... youth tend to hold back their feelings, don't disclose, live in denial or shame, " Robbins said.

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He believes that as many as a third of employees who are fired don't know why they were let go or are in denial about the real reasons.

WSJ: Turn a Firing or Layoff Into a Learning Experience

We start losing our hearing as early as our 20s, but most people aren't aware of it -- or they're in denial.

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"Almost all of these companies are in denial like an alcoholic--'I don't have a problem, just sprinkle holy water on this and I'll be fine, '" Marsal told me.

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People who struggle with addictive behaviors are often in denial about their situation or are unwilling to seek treatment, and they don't recognize the negative effects their behavior has on themselves and others.

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