I've been thinking something along these lines recently too. A single neuron seems like an absurdly complex device. I doubt they are really similar at all to "artificial neurons" except in some vague abstract sense. So the brain is essentially a network of billions of powerful, hyper-efficient computers (not to mention all the other nerves in the body), whose function, communication protocols, and network topology have been developed for millions of years in such a way that has lead to human intelligence.

And yet it still takes decades to develop a human mind. Even just to become competent with a single language takes years and it requires much more than just learning that language. If we could develop an AI system that hypothetically could achieve human intelligence, could we even train it to that level faster than it takes a human mind to mature? Is there some kind of maximum rate at which the process by which "intelligence"- whatever that may mean exactly- can be reliably run?