“Since psychological studies first began, people have given themselves top marks for most positive traits. While most people do well at assessing others, they are wildly positive about their own abilities, Dunning said.
That's because we realize the external traits and circumstances that guide other people's actions, ‘but when it comes to us, we think it's all about our intention, our effort, our desire, our agency — we think we sort of float above all these kinds of constraints,’ he said.”
[source: https://www.livescience.com].