Balderdash. That’s nothing like a real expert acts.

Actual experts use a lot of words of doubt in their speech on subjects of expertise because they are aware of so many special cases.

I’m an expert on several things, for example the C++ programming language. Like all real world things, C++ has a huge number of different possibilities and corners, so I am always using “words of doubt” when I speak because there simply isn’t time to go into all the different cases.

I say, “most of the time”, “usually”, “in common usage”, “except in edge cases” because I know all of the exceptions, and I don’t want to lie to you, but you also wouldn’t be interested in all these weird special cases either.

The sorts of people who never use “words of doubt” are generally people who aren’t actually competent — Dunning-Kruger victims.

I’m sure that acting as if you are all-knowing will sell more books — but it won’t make you an expert, because that’s not how actual experts — that is, people with actual competence in the field — work.

I note with amusement that there’s no hint as to the actual content of the book except it’s “timeless”. A skeptical reader of this article might ask themselves, “If that book is so all-fired great, why doesn’t the writer link to it in the article?” It is my tentative theory that if we could see the actual book, no one would take the article seriously.