Studies have uncovered the following:

People who are doing really badly, they're performing really poorly, tend to think that they're doing quite well. Which is really interesting because if you ask them to predict how other people will behave in general they're largely accurate. They actually get other people in general right more or less but they really get themselves wrong dramatically.

On the other hand, the select few students at the top of the class who are doing as well as they predict, tend overrate the abilities of their classmates. They're rather accurate at knowing how they've done, but because the test is so easy for them, they think it's easy for everybody… they're often surprised at how poorly other students do, they had no idea.

Maybe making New Year's Resolutions, wherein we take a more objective look at ourselves, is a good idea. And if someone critizes, listen. The possibility is that they may have something valid to say.