Secrets have power. And that power diminishes when they are shared, so they are best kept and kept well. Sharing secrets, real secrets, important ones, with even one other person, will change them. Writing them down is worse, because who can tell how many eyes might see them inscribed on paper, no matter how careful you might be with it. So it's really best to keep your secrets when you have them, for their own good, as well as yours.