Metacognitive monitoring is an extremely important ability that predicts a wide range of outcomes. However, do people have insight into their own metacognitive monitoring capacity? This study measured participants' perceived metacognitive monitoring abilities using a novel psychometrically validated questionnaire (Study 1) and then examined how well survey responses aligned with online measures of metacognitive monitoring (resolution, discrimination, sensitivity, efficiency) taken from confidence ratings participants made while performing a perceptual decision-making task and Raven's Progressive Matrices (Study 2). We found a negative correlation between the questionnaire responses and many of the online measures of metacognitive monitoring - those who reported being better at metacognitive monitoring, in fact tended to be worse according to the online metacognitive ratings. This occurred because, in general, high self-perceptions of monitoring ability were, in fact, related to higher confidence and lower cognitive performance. These findings suggest that we may have inaccurate insights into our own metacognitive monitoring capacity and questionnaire-based measures of metacognitive abilities may be problematic as they may represent unrealistic self-perceptions.