Why he’s cool: Is the richest man in the world. At 53, his estimated net worth is $40 billion.  

What he did: Best-known entrepreneur for the personal computer revolution. He created the Bill & Melinda Gates Foundation, which has donated millions to charity.  

What can you learn from him: You don’t always have to graduate college or university to be successful.  

What he owns: 66,000 sq ft earth-covered home in Medina, Washington. It boasts a 60 ft. swimming pool with an underwater music system; 2500 sq ft gym; 1000 sq ft dining room and a large home library.