Grant also gives the example of a survey that asked respondents to rate their knowledge in comparison to other people. They were also prompted to take a test that assessed their real level of knowledge. The survey showed that people who considered their knowledge better than that of others significantly overestimated themselves. The result of their overconfidence is a failure to learn new things and modify their views. In the end, that leads to ignorance and arrogance.
Overconfidence doesn’t let us see our flaws.
Suggestion : We teach ourselves to be modest, but in a self-assured way. Not only does confident modesty allow us to recognize our flaws, but it enables us to work at overcoming them.