How well can the truth stay buried?

Knowing the complete truth will never be in many instances, or people take great strides to hide it. Parents hide truth from children, and vise versa, spouses from each other, employers from workers, politicians from the public, and so on, and so on. Sometimes the lie can stand for decades then some long lost archives or file brings the truth to light. Sometimes a participant spills the beans to ease a guilty conscience. Other times it comes out in the effects the departed left behind and can no longer protect. Some of the time, the truth is right there but will never be known completely, as in the OJ and De Anza baseball team rape trial. Do eventually most truths come to light, or are most buried so deep we do not even know they exist?