Self-assessments are often prone to error. Past research has identified cognitive and motivational biases that lead self-assessments astray. In the present paper, we discuss how behavior shaped by social norms leaves the negative information that people require for accurate self-assessments invisible. First, social norms lead people to suppress critical feedback in favor of more positive evaluations. Although people recognize that they prefer to provide positive feedback to others, they fail to consider that they might be the recipient of incomplete feedback. As a result, they are left with overconfident self-impressions. Second, social norms lead people to hide their own negative emotional experiences from others. Again, people are aware that this positivity norm influences their own behavior but do not apply this knowledge to their understanding of others. As a result, people regard their own negative emotions as more socially aberrant than is actually the case.