Weighed against the other options, measured and practiced and explored--most things came down to choice. It wasn't fate or chance that led Orin Donaldson to fall in love with Freya Vollan instead of the dark-haired business woman his mother would have preferred. It was choice that made the two marry early in their relationship (a fact neither regretted, even in the heart of the harshest fights their children witnessed)--and it was choice that led them to begin building a family together.
It was a choice to raise their sons as brothers, to take the adopted illegitimate son of a failing business rival and the illegitimate son of Orin himself and try to craft family from that, to try to build both heritage and succession plan. It wasn't exactly choice that made Blake more oblivious to it then his brother, that made him soar in the light of competition rather than falter--but it was maybe a choice to remain so, to attempt to deny that he was in fact pitted against his brother for their inheritance, for the place in the family company he'd never been certain he wanted anyway.
Boys grew into teenagers and into young men and along the way something fractured between Blake and his brother, something fragile shattered between the two, something Blake never saw as being tentative, but the hairline fractures were there, wispy fine and waiting for weight to make them fall apart--it happened at the end of secondary school, on the precipice of the brothers going to university--Blake to study veterinary science (which his father called endearing in the way that made it sound like misguided), his brother for business. It was a fight between his brother and Orin that sparked it--when Blake stepped in to mediate, his brother turned on him, vicious in a visceral way Blake hadn't ever expected. By the end, Blake knew that not only was his brother adopted (which didn't exactly matter to him), but his mother wasn't his birth mother. It was enough to drive him to break ties with the family, to go to school as an independent man and pursue interests unrelated to what he had been groomed to do.
In many ways, it was a relief. Though Blake largely cut ties with Orin through his schooling, he maintained contact with Freya--who despite not being his biological mom was as maternal and warm a figure as ever. School was more difficult than anticipated, but Blake enjoyed the challenge, enjoyed the way it kept his mind from fixating on the troubles with his family--it would have been perfect, except that he kept getting pulled into the family business. He reconciled with his brother, but his relationship with Orin remained strained--it became even more strained as his brother revealed his was starting up his own competing company and Blake refused to encourage him to stop. In fact, Blake encouraged him--which was probably a blow to his father, was probably the first time that Blake made it clear that he wasn't just his father's son.
It was all about choices. In the end, Blake decided he needed more distance. He moved to the states, where he found a job he liked working with animals for charity--it was hard and heart-breaking, but it was distracting, the kind of work he could throw himself into to keep his mind off of things. He made friends, he got involved. It took almost a year for him to reconcile with his father, and when he did it was a result of Freya being ill (it was skin cancer, and the fact that he could only support her over Skype made him feel like a failure of a son) more than of a change of heart. He's come to appreciate his independence, to enjoy the opportunity to find his own path, and to make his own name, well--he isn't sorry for how things turned out. If he also happens to have his own set of secrets (like the name and Boston home address of his birth mother), then his brother isn't the only one who can be crafty.