The 2011 TIME 100

Larry Page has never been afraid to think big. When I was his graduate adviser at Stanford, he and his friend Sergey Brin had the brash idea of giving everyone an instantaneous way to find anything on the Web. I was skeptical, but when their student project became one of the world's most powerful companies, the vision proved not to be so crazy after all.

Like many innovators, Larry, 38, loves grand quests. I've seen him challenge a Googler pitching a new idea by saying, "You're not thinking big enough."

As Larry returns to his leadership role as Google's CEO, he will surely keep taking risks. He will continue to push Google to innovate. I expect him always to be a bit quirky, to raise hackles and to pursue things that seem unreasonable and unreachable — until the very moment they become a reality.

Winograd is a professor of computer science at Stanford University