At best, Ferrucci suspects that Watson might be simulating, in a stripped-down fashion, some of the ways that our human brains process language. Modern neuroscience has found that our brain is highly “parallel”: it uses many different parts simultaneously, harnessing billions of neurons whenever we talk or listen to words. “I’m no cognitive scientist, so this is just speculation,” Ferrucci says, but Watson’s approach — tackling a question in thousands of different ways — may succeed precisely because it mimics the same approach. Watson doesn’t come up with an answer to a question so much as make an educated guess, based on similarities to things it has been exposed to. “I have young children, you can see them guessing at the meaning of words, you can see them guessing at grammatical structure,” he notes..
This really resonates with me, especially the point about the brain being a guessing machine rather than an understanding machine. From watching my son learn and grow I noticed there was a point where he was still guessing, because he didn't really know yet, but his guesses were so accurate he was right every time. But he was still guessing.
Perhaps by the time we really understand something it's because we're already on to guessing the answer to something even bigger.