Elon Musk's incredible success is attributable to his intense focus on priorities and his ability to say no to distractions, according to his ex-wife Justine Musk. She emphasizes that Musk's achievements are not due to magic, but rather his relentless drive, sacrifice, tough decisions, and unshakable commitment to the bigger picture. The key takeaway is that true success demands not just hard work, but smart work and sustained focus.