March 27, 2009. I was fine the night before. The little cold I’d had was gone, and I’d had the first good night’s sleep all week. But when I woke up Friday morning at 6:15 and got out of bed, the world was whirling counterclockwise. I knocked against the bookcase, stumbled through the bathroom doorway and landed on my knees in front of the sink. It was as though I’d been tripped by a ghost lurking beside the bed. Even when I was on all fours, the spinning didn’t stop. Lightheaded, reaching for solid support, I made it back to...