For the sake of dialogue I'll assume you are actually serious with that comment.So people have different levels of confidence? Does it matter in life?
Yes it matters. it matters a lot.
1)it's the same phenomenon that give con-men the charm they have.
2) it's one of the underlying reasons for the glut of misinformation.
3) It can contribute to high anxiety to those prone to it.
4) It's the reason Trump can out persuade large groups vs experts.
5) It's a reason that people get promoted or hired over others that may be better candidates.
that's 5 reasons of the top of my head.