20 year old human has
* heard ~220 million words, talked 50 million words.
* read ~10 million words.
* experienced 420 million seconds of wakeful interaction with the environment (can be used to estimate the limit to conscious decisions, or number of distinct 'epochs' we experience)
From a machine learning perspective human life is surprisingly small set of inputs and actions, just a blip of existence.
But also humans have been speaking for so long it's silly to imagine we don't have some evolved language structures in the brain. I don't know why anyone would single that out for skepticism while not questioning e.g. the brain structures for sight, sound, emotions, navigation, etc.
That's Chomsky's argument. A small set of constraints for organizing language.
Put a kid from one language tradition in a spot with a different language tradition, and they won't be able to learn it.
Eg. kids with native mandarin speaking parents adopted to native Indo-European parents fail at learning English, and will be better at learning Mandarin than their peers with Indo-European heritage.