On the day he unveiled the Macintosh, a reporter from Popular Science asked Jobs what type of market research he had done. Jobs responded by scoffing, "Did Alexander Graham Bell do any market research before he invented the telephone?

I actually think Bill Gates is conventionally smarter, even though it's a dumb word, but mental processing power - I've watched him use four different screens, process information, get to the right answer, boom boom boom.

I have my own theory about why decline happens at companies like IBM or Microsoft. The company does a great job, innovates and becomes a monopoly or close to it in some field, and then the quality of the product becomes less important. The company starts valuing the great salesmen, because they’re the ones who can move the needle on revenues, not the product engineers and designers. So the salespeople end up running the company.

Sometimes, to relieve stress, he would soak his feet in the toilet, a practice that was not as soothing for his collegues.

Leonardo da Vinci had such a playful curiosity. If you read his notebooks, you'll see he's curious about what the tongue of a woodpecker looks like, but also why the sky is blue, or how an emotion forms on somebody's lips. He understood the beauty of everything. I've admired Leonardo my whole life, both as a kid who loved engineering - he was one of the coolest engineers in history - and then as a college student, when I travelled to see his notebooks and paintings.

Most innovation comes from people working together, collaborating in teams.

People who know what they’re talking about don’t need PowerPoint.