I will never reveal my dreadful secrets, or rather, yours.

A man burdened with a secret should especially avoid the intimacy of his physician.

Never tell all you know — not even to the person you know best.

I don't like talking about my personal life. My age is not known to the public and I am not revealing it because I see no reason to.

Unfortunately, this category of secret is itself so secret that it's very existance is secret, and he can't actually reveal it to anyone.

Never reveal all of yourself to other people; hold back something in reserve so that people are never quite sure if they really know you.

I can’t reveal the mystery to either saint or sinner; I can’t state at length what I’ve said curtly; I achieve an altered state that I can’t explain; I have a secret that I cannot share.

There are some secrets which do not permit themselves to be told.

A man is more a man through the things he keeps to himself than through those he says.

It is true that I intentionally try to keep it (my private life) from everyone. I don't like to show off my private life. Maybe that's why it makes me mysterious?

Whatever you agree to do, observe.—Do not divulge secrets.

A secret is not a thing you're not supposed to tell; it is a thing that can't be told.

I don't like discussing my private life in public. It feels strange.

Every man has some reminiscences which he would not tell to everyone, but only to his friends. He has others which he would not reveal even to his friends, but only to himself, and that in secret. But finally there are still others which a man is even afraid to tell himself, and every decent man has a considerable number of such things stored away. That is, one can even say that the more decent he is, the greater the number of such things in his mind.