

My guess is it’s sensory input and other information that doesn’t make sense once the brain has started structuring itself towards what’s needed for adult functions. I forgot where I heard it or how they tested it but iirc babies can differentiate a much wider variety of vocalizations than adults, even to the extent of pretty much all the different sounds a human mouth can make, but that as they learn language they lose the ability to differentiate sounds that they don’t need to to speak and understand their first language (like how English speakers struggle to differentiate Ш and Щ but a Japanese person might struggle with R and L). So it’s probably a bunch of info like all those different little sounds you just don’t have the structures to process the data anymore. Like trying to access a niche filetype after you uninstalled the software you used to make and read it.
you get me