For as long as I can recall, I've been unreasonably fascinated by other people's daily schedules. It thrills me to learn, for instance, that Karl Lagerfeld always sleeps for exactly seven hours, no matter when he goes to bed; that he drinks only Diet Coke, and rarely exercises "because my doctor said it's not necessary". My bursting mental library of similar trivia includes, naturally, Churchill's daily 90-minute siesta, but also the fact that Paula Radcliffe is usually in bed by 10ish and that Will Self keeps a stove on his desk to brew "strange infusions" of tea while he writes. These days, I encounter such nuggets most frequently in media profiles of web entrepreneurs, presumably because they're our era's most envied role models. Thus I've discovered that Twitter co-founder Jack Dorsey divides his week thematically: Tuesdays for product development, Wednesdays for marketing, etc. Maria Popova, who runs the popular Brainpicker account on Twitter, gets so much reading done by taking her Kindle to the gym. And Facebook's chief operating officer, Sheryl Sandberg, leaves the office at 5.30pm daily, for dinner with her children at 6pm. At any hour of the day, I can tell you what four or five famous people are probably doing, should you wish to know. Which, I appreciate, you maybe don't.