The earth was formed roughly 4.6 billion years ago. The earth cooled. One-celled organisms evolved into complex animals, peaking with the era of the dinosaurs. The dinosaurs were beset by a world-wide calamity, likely an asteroid strike. The world's animal population was devastated. Only the most resourceful and robust animals survived. Over time, those animals evolved further, eventually developing large problem-solving brains and spreading over almost the entirely of the earth's dry land. Today, modern humans stand at the top of this billion year evolutionary odyssey, the crowing achievement of either God's great plan or the undisputed champion of Darwin's evolutionary race to the top.
So... can someone tell me why the hell I continually bite the inside of my mouth when chewing food? Anyone?