T he opening section of I Want You to Be Happy is an excellently droll and surefooted description of a man and a woman meeting in a bar, trying to make conversation over the music and flirting vaguely. They establish that she is 23 and that he is 35. All the specifics – the name or location of the bar, the music, even the names of the couple – are for now redacted: “After a while, the twenty-three-year-old woman raised her voice and, referring to the thirty-five-year-old man, asked her short-haired friend: ‘How old do you think he is?’ The short-haired friend surveyed the thirty-five-year-old man’s face; thought for a moment. ‘Forty?’ The twenty-three-year-old woman snort-laughed. ‘He’s thirty-five.’” Jem Calder, like his protagonists, is bang on trend.…