Read Ecclesiastes, and you'll wonder what such a seemingly modern/timeless take on reality is doing among the other books. It's a bit hard to parse, but read a paraphrase to get started.
(Also recommend Heinlein's short story Ordeal in Space, on the subject of fear/phobia/duty.)
(Also recommend Heinlein's short story Ordeal in Space, on the subject of fear/phobia/duty.)