Moravec's paradox states that, for AI, the hard stuff is easiest and the easy stuff is hardest. But there's no easy or hard; there's only what the network was trained to do.
The stuff that comes easy to us, like navigating 3D space, was trained by billions of years of evolution. The hard stuff, like language and calculus, is new stuff we've only recently become capable of, seemingly by evolutionary accident, and aren't very naturally good at. We need rigorous academic training at it that's rarely very successful (there's only so many people with the random brain creases to be a von Neumann or Einstein), so we're impressed by it.
