They would have probably been really surprised that we'd have a superhuman Go player before we had a robot that was just average at picking up arbitrary items.
It really seemed unfair that he had had the fun of building the robots and than said I shouldn't do it. It took years to realize what he was really saying (a statement I could make about many things he said).
Interestingly the myelin sheath around your peripheral nerves thins as you grow. I have always assumed this is to reduce capacitance so that signal propagation time between (say) your fingertips and brain remains roughly constant as your arm gets longer. I don't know if anyone has ever studied this though.
Myelination continues Into adulthood btw -- you can see a change in the distribution of white matter due to learning a new language for example.
I've never worked with machine learning in robotics, but my understanding is that physics simulators are still insufficient environments for training state-of-the-art robotic agents. Especially when using reinforcement learning or a similar algorithm, many models are trained with several real robots picking up real objects.