In the 2015 biography, Elon Musk: Tesla, SpaceX, and the Quest for a Fantastic Future, Ashlee Vance shares the story of how Musk stopped working with his long-time executive assistant in early 2014.

According to Vance, the assistant, Mary Beth Brown, asked Musk for a significant raise after she’d been working with him for 12 years. In response, Musk told Brown to take two weeks off, during which he would assume her responsibilities and see if she was really critical to his success.