The world's richest people

Topping Forbes' list this year is Microsoft founder, anti-malaria crusader and philanthropist: William Henry Gates, worth $75 billion (69 billion euros). You probably know that he founded one of the most important tech companies in the world, but did you know that he only plans to leave each of his children $10 million? He says leaving kids huge amounts of money doesn't do them any favors.

This 79-year-old Spaniard founded the fashion retailer Zara in 1975. His net worth is estimated at $67 billion. An extremely guarded person, Ortega has only ever granted three interviews to journalists. He is an avid equestrian and often wears the same outfit to work: blue blazer, white shirt and gray slacks - none of which are Zara products.

The "oracle from Omaha" was already playing the stock market at the sprightly age of 11. Today, his stock picks move markets. This 85-year-old investing guru is estimated to have a net worth of $60.8 billion. As a teen, he was a shrewd entrepreneur, delivering newspapers, selling old golf balls and polishing cars. But his application to Harvard Business School was rejected.

The fifth richest man in the world, Jeff Bezos is the richest figure in tech, worth $45.2 billion. The founder and CEO of Amazon, Bezos knows the importance of customer satisfaction - so much so that he even lets customers email his directly. If he sees something requiring special attention, he forwards it along to the respective Amazon department himself with a single remark: "?"

Mark Zuckerberg is the sixth richest person in the world, the second richest person in tech and the richest person under 40. According to Forbes, he's worth $44.6 billion. But what might surprise you about the 31-year-old Facebook founder is his Twitter profile, @finkd: He has 402,000 followers despite only having ever tweeted 12 times. His first post? "Never thought I'd be on a boat."

You may not know this about Larry Ellison, the founder and former CEO of Oracle, but he earned his wings building databases for the CIA. After dropping out of the University of Illinois and the University of Chicago, he founded Oracle in 1977 as a provider of database software and is worth $43.6 billion today, making him the seventh richest person in the world and No. 3 in tech.

Google co-founders Larry Page and Sergey Brin are worth a respective $35.2 and $34.4 billion, making them the 12th and 13th richest people in the world. Their search engine began as a research project at Stanford University, back when the World Wide Web was in its infancy, as a way to quantify and qualify "backlinks" between Web pages, or websites that link back to other pages.

The daughter of L'Oreal founder Eugene Schueller, Liliane Bettencourt inherited her family's cosmetics fortune in 1957 and is now the richest woman in the world, worth $36.1 billion. She also has a stake in the Swiss food giant Nestlé, with which she runs the L'Oreal group. Bettencout was embroiled in a tax scandal in 2010 after her butler secretly recorded some of her private chats.

This year, the title of world's youngest billionaire goes to Alexandra Andresen (above right), a 19-year-old Norwegian and accomplished equestrian. But she didn't amass her $1.2-billion fortune with horses. Rather, it was given to her by her father, Johan Andresen, who bequeathed a 42 percent stake in the family business to each of his daughters, including Alexandra's 20-year-old sister Katharina.

Before his death at the age of 99, John R. Simplot was the oldest-living billionaire in the world worth $3.2 billion. He amassed his fortune with potatoes, beginning as a farmer before moving into sorting and processing. He eventually founded the world's largest potato-dehydrating plant and his dried spuds fed many U.S. troops during World War II. He also developed the first frozen French fries.

The mom and pop store pictured above was founded in 1913 near Essen, Germany. It survived the crushing hyperinflation of the Weimar Republik, the fall of Nazi Germany eventually grew into Germany's largest discount supermarket chain, Aldi. Beate Heister and Karl Albrecht Jr., worth a combined $25.9 billion, and their cousin, Theo Albrecht Jr., worth $20.3, are the children of Aldi's founders.

Susanne Klatten is Germany's second-richest woman after Beate Heister of Aldi. Susanne, together with brother, Stefan Quandt, owns nearly 50 percent of the German automaker BMW. She is also known as the driving force behind Altana AG's transformation into a renowned pharmaceutical company. According to Forbes, Klatten is worth $18.5 billion.