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.

Smart people are a dime a dozen. What matters is the ability to think different... to think out of the box.

It seems perverse to focus too much on the casualties or hardship in Afghanistan ...[Showing the misery of Afghanistan ran the risk of] promoting enemy propaganda...we must talk about how the Taliban are using civilian shields and how the Taliban have harboured the terrorists responsible for killing close up to 5,000 innocent people.

Ed Woolard, his mentor on the Apple board, pressed Jobs for more than two years to drop the interim in front of his CEO title. Not only was Jobs refusing to commit himself, but he was baffling everyone by taking only $1 a year in pay and no stock options. I make 50 cents for showing up, he liked to joke, and the other 50 cents is based on performance.

Picasso had a saying - 'good artists copy, great artists steal' - and we have always been shameless about stealing great ideas.

You know, one of these things that happened in the '60s and '70s was this confluence of, sort of, a counter-culture with computer culture.