Every writer yearns to create a book that will seize the moment — to perfectly encapsulate the problem of an era before other people even notice the problem exists. Of course, that almost never happens. Mostly we’re happy if we can manage to explain, in an interesting way, something people already know is going on. But Betty Friedan won the gold ring. When “The Feminine Mystique” emerged in 1963, it created a reaction so intense that Friedan could later write another book about the things women said to her about the first one (“It Changed My Life”). If there’s a list of the most important books of the 20th century, “The Feminine Mystique” is on it. It also made one conservative magazine’s exclusive roundup of the “10 most harmful books of the 19th and 20th centuries,” which if not flattering is at least a testimony to the wallop it packed.