It was 15 years ago today that Bill Gates stepped down as CEO of Microsoft.

While he stayed involved as chairman and chief software architect, it was the start of his major life transition. Here are seven keys to his success--taken from the history of his life and applied to one endeavor after another.

1. Get in early--and learn.

I don't know if there are shortcuts in life, but there are certainly head starts.

Gates had a big one. In 1969, when he was in eighth grade--when very few schools had any kind of computer system--his school bought an early machine along with blocks of processing time. Gates was excused from regular math classes to learn to program, and became enthralled with it. His first computer program: a tic-tac-toe program.

2. Seek forgiveness, not permission.

Too many people fail to succeed because they hold themselves back. Whether it was youthful folly or instinct, Gates didn't fall into this category.

As an early example--that computer in eighth grade? When the school's funds eventually ran out, Gates (with his friend Paul Allen and other students) exploited bugs to obtain free computer time. When they were caught, he and the others traded their bug-finding ability for more free computer time.

3. Value your work.

Another big problem many people have--they are afraid to ask for money. Here again, Gates never had that problem. At age 14, he was writing code for a local company's payroll program; by age 17, he and Allen launched a company that used an early computer program to help count road traffic. 

Gates also pushed to get paid during the 1970s, when business was seen as "square" to put it lightly. After he realized that computer amateurs were using pirated versions of his software, at 21, he wrote an "Open Letter to Hobbyists" telling them to "pay up" so he could "hire 10 programmers and deluge the hobby market with good software." 

4. Learning matters more than school.

Gates was a good student--he scored almost perfectly on the SAT--and he was from a family that valued education. He enrolled at Harvard at 17, but didn't declare a major and instead spent his time using Harvard's computers.

By his second year, however, Gates dropped out of Harvard to start a company with his high school friend, Allen--and begin his real education.

5. When you're in charge, take charge.

It's funny how perceptions change, but when he was running Microsoft, Gates had a reputation as a difficult, extremely competitive boss. Much like his contemporary Steve Jobs, descriptions of his reaction to employees he disagreed with in meetings were harsh. One described Gates's criticism as "devastating." 

At the same time though, he took responsibility. During the first five years, when he was overseeing all of the business aspects of the company, he also oversaw (and often rewrote) every line of code in the company's products. If you're old enough to have used MS-DOS or the original version of Windows, you've used a product Gates helped code.

6. Be the guy who predicts the future.

Obviously easier said than done, but Gates saw the future first at several key moments. One of them--and this is a classic story--came in 1980, when he negotiated a deal to license the DOS operating system to IBM for a low $50,000, but had the foresight not transfer the copyright. As a result, Microsoft was able to license the OS to other vendors who cloned IBM's machine, thus making a much bigger and more profitable market for his company.

More chillingly: Gates has said recently he's concerned about the threats of super-intelligent machines on humanity. Let's hope he's not seeing this prediction as clearly. 

7. Take on a big enough mission.

In some ways this should be the first item on the list, as truly successful people first choose endeavors worthy of their time.

In Gates's case, fast-forward to the 2000s, after he transitioned out of Microsoft and became a full-time philanthropist. Using the examples of John Rockefeller and Andrew Carnegie (and the mentorship of Warren Buffett), Gates and his wife, Melinda Gates, are among America's most generous philanthropists, focusing on "big problems" that they believe governments around the world are incapable of solving.