Ecclesiastes

Ecclesiastes was a turning point in my case.

Eccleisastes — Holy Bible A book on the vanity of life

I would almost considered quoting the great ancient literature a cheat-code but I still do really like the Ecclesiastes. From the other end of the spectrum, "The Adventure of the Dancing Men" is the book/story that inspired my interest in cryptography. In the end I never worked in infromation-security but I did enjoy it from my 10 years til I left college, and I still do enjoy going for puzzle-hunts with some of my friends :)