He said people who were right a lot of the time were people who often changed their minds. He doesn’t think consistency of thought is a particularly positive trait. It’s perfectly healthy — encouraged, even — to have an idea tomorrow that contradicted your idea today.
He’s observed that the smartest people are constantly revising their understanding, reconsidering a problem they thought they’d already solved. They’re open to new points of view, new information, new ideas, contradictions, and challenges to their own way of thinking.