Truly realizing that the own existence is meaningless would drive most people insane

Agreed. If by “nobody” they mean “the average person...” my question becomes- how many of those people have you gotten to know, deeply, and spent loads of time with? There’s an “immature wisdom” in the statement- the kid who reads something for the first time and thinks they have come into some deep and hidden knowledge surely no one else could know. But the fact that everyone you meet doesn’t walk around spewing their life philosophy and doubts or quandaries in what is the universe... doesn’t mean they do t have their questions... or their own answers.

To the contrary- many religious folks would tell you they believe they have the answers to those questions. In fact- that’s kinda what most religions are isn’t it? Someone’s search for- or answer for- questions about the purpose of life? But people commonly dislike when others bring their religion- their theories on purpose- and wave it around right?