Because after a time having a secret and nobody knowing you have a secret us no fun. And although you dont want others to know what the secret is, you want them to at least know you have one.
Secrets are hard but solvable problems and we should talk about them. It's hard to work toward a radically better future if you don't believe in secrets.
Signs cannot be represented, in a spy's report, so damningly as words.
The password is a flicker of an eyelash.
If knowledge is power, clandestine knowledge is power squared; it can be withheld, exchanged, and leveraged.
There are the things that are out in the open, and there are the things that are hidden. The real world has more to do with what is hidden.
There must be a secret hidden in this book or else you wouldn't bother to read it