Lack of predictability is dangerous. On some level we all know this. It goes back across the centuries to, for example, when we lived in the shadows of great castles, daily expecting a drunken and half-insane baronial lord to emerge and do something to destroy our lives. This, and a million stories like it, explain the urge to gated communities, to identical malls, to burgers that taste the same across the planet. They are predictable. secure and safe and they are indirectly part of the drive for happiness. Actually the word happiness is wrong here, When we refer to the tepid glow we get from all our stuff and mechanisms we have to keep safe, to keep our families ever-smiling, surrounded by air bags both real and metaphorical, we mean contentment. And the dirty secret of our contentment is that we know, again on some deep level, that it's the best we've ever had it. Our ancestors were grindingly miserable. Worse that that, they were survivors and survivors are rarely pleas...