I think people also have a very hard time conceptualizing the amount of time it took to evolve human intelligence. You're talking literally hundreds of millions of years from the first nerve tissues to modern human brains. I understand that we're consciously designing these systems rather than evolving them, but nevertheless that's an almost incomprehensible amount of trial and error and "hacking" designs together, on top of the fact that our understanding of how our brains work is still incomplete.