The reason why most people cannot keep secrets is because they need a sanction/warrant/permission from others for being the way they are or for doing the things they did. Seeking such an approval they tell their secrets to others and find themselves at the mercy of the people who now know their true self. The only way I know to keep secrets is to realize that I need no warrant or sanction upon my being. As long I live up-to my standards I am that warrant and sanction. My moral stature is not at the mercy of other people’s actions or opinions. Once you realize this, you too can keep secrets. Be comfortable with yourselves!