Most people know three things about Bill Gates: He's the richest man in the world He cofounded one of the most successful tech companies of all time in Microsoft He's an extremely generous philanthropist through the Bill & Melinda Gates Foundation. But despite his philanthropic efforts and online presence , there are a lot of things about Gates that many are unaware of. Here are 17 facts you probably didn't know about Bill Gates. View As: One Page Slides 1. As a teen at Lakeside Prep School, Gates wrote his first computer program on a General Electric computer. It was a version of tic-tac-toe where you could play against the machine. CBS/YouTube Source: Science Museum 2. Once his school discovered Gates' coding abilities, they let him write the school's computer program for scheduling students in classes. Gates slyly altered the code so he was placed in classes with a "disproportionate number of interesting girls."