Dr. Dre ran into business partner Jimmy Iovine one day and asked him for feedback on a potential sneaker endorsement deal. In a quick conversation, they realized shoes were basic - anyone can endorse a shoe - but they needed to create something that represented Dre. "Speakers and headphones", they both realized.

That idea became Beats by Dre. A million flew off the shelves in the first year. A few years later, it sold to Apple for $3 billion.

Their conversation was ten minutes.

It's just one scene in the riveting HBO documentary, The Defiant Ones. On the day of Apple's controversial iPhone 8 announcement, it is worth revisiting how Dr. Dre, with his partner Iovine, created the most important Apple acquisition in recent memory.

You need a tribe: This much is clear: Without talking to Iovine, Dre would have never done the Beats headphones. It is telling that even Dre, an admitted loner, needed insight, validation and support from someone he trusted. As Onlyness author Nilofer Merchant told me recently, "Until you have a group of people who can back you personally and give you a safe enough space to explore your ideas, you can never take the psychological risk to pursue your ideas."

You need a voice: Until Beats, headphones were those extra, throwaway accessories that came with your phone or sold as an afterthought with your devices. Dre was someone respected for his music, but, more importantly, he was someone who was known for his passion for the art. It's as much as Virgin being a reflection of Branson's eccentricity or Microsoft showing the vision of Gates. A good idea is fine, but a great idea is embossed with the soul of its maker.

You need an addiction to growth: One of the patterns in The Defiant Ones is how many times Dre rose to the top of a business, only to walk away when it was clear that he could no longer grow. He went from an inner-city DJ to a billionaire Apple entrepreneur in just three decades. That growth only occurs when you are OK leaving your comfort zone - and challenging yourself in ways other people would never expect.