Yeah, Helen Keller isn’t the greatest example, ’cause she *had* vision ’til she was 2? or 4? I forget. Anyway, she had PLENTY of processing-time to get LOTS of raw data to be able to utilize later on in her Water moment, and plenty of stuff to analogize to in order to increase her knowledge about her surroundings, even if her input mechanisms were severely stifled.
Basic circuits were formed; the rest is subconscious analogizing.
Even when I learned about her in grade school, and saw some dramatic TV movie, I wasn’t terribly impressed by Helen Keller.
I’m 1/2 deaf and 1/2 blind myself – imagining myself in her shoes wasn’t hard when I was 8, or now, but I like what she did with her life, and I honestly was more impressed by the teacher than by her.