Everyone has flaws. You don’t always see them because we don’t always do much more than scratch the surface with many people we know.
The longer and better you know someone, the more aware of their flaws you become. It may explain why some spouses become less enamoured with each other over time. It may explain why some friendships never last.
I would assume we’re more accepting of the flaws in others that we share as our own flaws, but I really don’t know. Perhaps, psychologically we would reject those who have the same flaws that we have?
I do know that characters in our writing have to have some flaws in order to hold the attention of the reader.
I know when I’ve watched some movies and heard the question, “What’s the worst thing you’ve ever done?”, it piques my interest. I really don’t think I want to know the worst thing most people have ever done. It does not truly define them any more than the best thing they’ve ever done would. It may show what they’re capable of; it may show the one thing they will never, ever do again.