The author responsible for the new revised edition of The Joy of Sex doesn’t have to imagine how useful the original 1972 version was for a generation of ecstasy-seeking couples, said Pagan Kennedy in The Boston Globe. British sexologist Susan Quilliam was 22 when the generously illustrated manual showed up on a table in her boyfriend’s Liverpool flat. “We disappeared into his bedroom and came out at the weekend,” she says. But while the book’s original author, Dr. Alex Comfort, had been ahead of his time in appreciating how the female body works, some of his tips seemed in need of radical updating. “He had a section called ‘Frigidity,’” Quilliam says. “I didn’t include that.”

Gone, too, in the new edition are sex on horseback and moving motorcycles, said Sarah Lyall in The New York Times. In are cybersex, condom instructions, and a whole section on the importance of the clitoris. Comfort wasn’t “anti-clitoris,” says Quilliam. “He just didn’t know.” The biggest change of all, though, may be in tone. Where Comfort was addressing an audience eager to explore sex as if it were a new playground, Quilliam felt it necessary to tamp down expectations. “I’m absolutely in favor of making sex fun,” she says. “I’m saying, ‘Let’s normalize this.’ Most people don’t have screaming orgasms every weekend. Have love, have sex. But don’t give yourself a hard time if you’re not doing it 24/7.”