I firmly believe, given enough time and technology, and barring we don't destroy our own selves like dumb asses of the highest order that mankind is.....I think we can achieve just about anything we can possibly think of. Which is a beautiful picture if we weren't so short sighted.

I have a brain injury from impact. Tho I am not a paraplegic or in a wheelchair, I have suffered some mental/neural maladies. I am pretty mobile, I read a ton of content off the internet. So, I function with some defficiencies. Imagine for those far worse off than I, like a paraplegic with significant brain/spinal damage. I always think 'I wonder if they have any kind of inner monologue?'

In a general sense, we loose very few of our memories over our lifetime. Yes there are caveats but, a majority still exist, our retrieval system lags. I realize it's a lot more complicated than this simplistic explaination. If we could somehow tap into that lost archived data bank, that would open up a lot litany of issues. Solving crime comes to mind.