Rule of the Rock

The Rule of the Rock is the antidote to ungrounded mystical or scientific speculation about the "illusory," ephemeral, or "holographic" nature of this universe. Should you ever start seriously thinking that the universe around you is nothing more than an illusion, pick up a (small) rock and smash yourself in the head with it. The empirical reality of the rock causing independently verifiable damage to your skull should instantly disabuse you of senseless and ungrounded speculation.