You could read this line and file it away as one of those quotable sixteenth-century one-liners that turn up on the internet with wildly varying attributions and no particular sourcing. But if you sit with it for a minute, Montaigne is describing something you already know from the inside. Something you probably did last Tuesday. You lay in bed at some point in the past week and rehearsed a disaster. Maybe it was a work problem. Maybe it was a c…