I teach OS security for a masters course. I don't know where my students are for any given semester - it's a mixture between experts who need a certification (I have taught someone who literally wrote the book on a major OS's security model) and people who have ended up on security entirely by accident. It is extremely hard to write something that lands for that entire range. "Finished highschool" is really not a precise determinator in the way "I am literally 5" is.