Gosh - technology amazes me sometimes.
Yes it is amazing, I remember my father making Radio's ,TV's and amplifiers with 'Valves' that would light up the living room (I still have a box full of different valves 807's, ECC83 are just two of many).
Then my father started my interest in electronics with a 'cat whisker' crystal set, then I started making my own 'germanium' transistor radio's etc., Then out came integrated circuits and things were getting smaller and smaller.
Interesting. I'm not sure about replacing brain cells though.
I said to my daughter the other day when she was doing her revising for her sats, I said in her life time there would be some small electronic memory chip implanted into the human body to help you remember and you could update it like we do with our computers today.
No not one of my predictions again.
I wished I followed up the one I remembered writing about when I was at junior school, because I was building my own radios, I put in an essay about one day you would be able to buy "Wind Up Radio's"
I should have taken a Patent out on it.