Earlier this week, Forbes magazine revealed the world's richest people in their annual billionaires list. Top of the pile was Bill Gates, reclaiming the money crown he last held in 2010. The Microsoft founder has an estimated personal wealth of $76 billion and has headed the Forbes list in 15 out of the last 20 years. But how did he reach the top? We trawled through archives of interviews and speeches to find the Gates recipe for success in his own words, revealing his wisdom, wit and an ability to think big. Click through the gallery to read some of Gates' most notable quotes.