Well my mistake, I didn't realize this point was still under contention. I was under the impression that it's common knowledge that new connections are not created in the brain after a certain age (15-ish as I recall) and all new connections must be formed from existing ones.

This is why e.g. bilingual kids learn new languages much faster than people who only speak one language, people who learn an instrument as a child can pick up new ones much faster, etc.

What is a personal theory of mine is that if you don't have language to understand a concept by a certain point you can never truly understand it. The only places I point to that support my theory are the few cases of children being raised away from humans [1] and this Pirahã story. It's pretty difficult to prove scientifically since it would require destroying someone's life.

But on this site, of all sites, I would expect discussion about it, not a simple down vote.

[1] I've heard of at least 2 seperate cases where through some odd circumstanced a child reached teenage years without learning any kind of communication with humans. After they were rescued, in both cases they were never able to grasp concepts much further than a young child (around where chimps who learn sign language get to). This is by no means conclusive, since they obviously went through an incredibly traumatic experience, but as I mentioned above, there is no easy way to apply scientific method to this theory.