i've always assumed that language was required to give your brain the abstractions needed to reference things in the past compared to your current perception (aka now), like an index. if you think about your earliest memories, they almost certainly came after language. i'd be interested to know if any of the documented 'wild child' cases (infants 'raised by wolves') ever delved into what the children remembered before, after being taught language as an adolescent.
There were efforts to teach them language as adolescents, but they didn't acquire it - as far as we know, it's not possible to acquire language if you don't do it as an infant.
This is similar to other brain functions that aren't present at birth and require stimulation, such as sight. That is, if your eyes are forced closed for the first few months of your life, you will never be able to see, even if later they are uncovered, and keep working perfectly. The brain functions responsible for interpreting visual signals can only develop if they get visual signals in a (quite short) developmental window - and we know this with quite a bit of certainty from quite cruel animal studies.
Language acquisition is not proven to be the same, as the required studies would be deeply unethical, but the few experiences with feral children are highly suggestive that the same applies.
i just had the uncomfortable thought that it's possible a disease could kill off everyone older than 1, sterilizing the species to language at some scale. for the few that survive, their world would be feral.
