Anyone who has ever had kids knows this. Little kids learn language and fully developed world models on a tiny amount of data compared to the massive hoards we shovel into our training systems. That data is also noisy and only loosely curated.
The author does mention this but I think he actually doesn’t give it enough importance. A person could read for their entire life and not approach what we shovel into GPT-3.5 or llama2, yet a three year old builds a trained language model from what must be near scratch.
It must be near scratch for the initial condition because the human genome is nowhere near large enough to contain that much “priming.” There can’t be a “base model” analogue or anything like that in there.