They know a great deal about the real world, unfortunately not always enough. They know less about the world of Sheker, unfortunately sometimes too much.
That is very well said.
In fact there are those who barely know a thing about the world of Sheker and get marriage at age 16 and es felt zei gornisht, there is nothing that they are missing and there marriages are very good and stable (not that I would let my kids get married at that age).
Then you have very “worldly”, knowledgable, mature people who are missing a whole lot of knowledge of the real world and their marriages are not davka good and stable.