Microsoft's new CEO Satya Nadella takes online courses in the morning.

Net worth: $45 million

His colleagues have called him “thoughtful,” “articulate” and “a great listener.” But Nadella, who moved to the U.S. to earn his master’s degree in computer science from the University of Wisconsin - Milwaukee, is not so easily seduced by his new role as Microsoft’s chief executive.

Nadella says he likes to read poetry from American and Indian poets, and he still signs up for online courses to expand his horizons, especially early in the morning.

“I’m a learner,” Nadella says. “I think the thing that I realized is, what excites me is that I'm learning something. I can learn something about some area. I can learn something from people. I can learn something from doing things differently. And I admire that in other people, too. I fundamentally believe that if you are not learning new things … you stop doing great and useful things. So family, curiosity and hunger for knowledge all define me.”