When Google co-founder Sergey Brin began openly dating Nicole Shanahan, in 2015, some members of his circle assumed it was a fling. Fresh out of law school, she was 12 years his junior, with few of the qualifications that might level the power dynamic with the world’s seventh-richest man. “I thought, okay, she’s fine,” a person close to the situation told The Daily Beast. “And then it went on.”
By the time they married...