In low-income countries, getting to a health post is hard. It's very expensive.

All lives have equal value. And so you say, 'why do poor children die when other children don't? Why do some people have enough nutrition or reasonable toilets and other people don't?' So those basic needs that, through innovation, actually it's very affordable to bring them...to everyone.

The early personal computers were not very powerful so the idea of feeding their program into a small amount of memory requires immense skill.

I believe that if you show people the problems and you show them the solutions they will be moved to act.

Success is a lousy teacher. It seduces smart people into thinking they can't lose.

With tech companies, whoever's the leader is always questioned, you know. They say, 'Is this the end of them?' And - there's more - more times people think that's the case than it really is the case.

Research shows that there is only half as much variation in student achievement between schools as there is among classrooms in the same school. If you want your child to get the best education possible, it is actually more important to get him assigned to a great teacher than to a great school.