"Where do people get the confidence to say that their work is so uniquely novel that it's "something that has never been done before in the history of the universe", that the field is obviously totally different from another field they know nothing about, etc. ?" --Dan Luu

I think it is less that these things "have never been done before" and more "we haven't bothered to learn anything from people who've done things like this before". Same with parenting.

Regarding the parent issue and disregarding companies for a moment.

Not sure what you mean exactly by having no clue. You mean things like the family finances / jobs / schools stuff or parenting rules or what to do with illnesses and stuff like that?

Because I think saying nobody has a clue is a bit harsh. Some people are indeed more organized and have a better grasp on their plans and outlooks. I wouldn't say my parents had "no clue" or could have afforded to have no clue about what was going on.

I often hear this and it's probably meant as some sort of encouragement or anti-impostor syndrome talk, but it can also backfire. There is indeed value in thinking about how your family is faring, whether the finances are working out, whether you should move for a better job. It would be foolish to say nobody has any clue, so doing anything without thinking about it will be just as good.