" His circuitry is all different,” she told her twin sister. His ambition differed in essence as well as degree. Whereas with others she could tell the point at which she might assert certain proprietary rights (the very first hints of nesting behavior), with this runner there was never any question about her rearranging his priorities. This rankled her from the start. She might have the ability to make him miserable, perhaps, but she swayed him not an inch from his path. He told her as much, and she found out quickly he meant it. There was something in the ferocity of his dedication that challenged the formula of her femininity. She responded to the challenge without even realizing she was doing so. "

― , Once a Runner