Insomnia is a variant of Tourette's--the waking brain races, sampling the world after the world has turned away, touching it everywhere, refusing to settle, to join the collective nod. The insomniac brain is a sort of conspiracy theorist as well, believing too much in its own paranoiac importance--as though if it were to blink, then doze, the world might be overrun by some encroaching calamity, which its obsessive musings are somehow fending off.