I've heard from Richard Dawkins (While he quotes someone else that I don't remember, think it's from one of his TED talks) that all the atoms in our bodies are swapped over our lifetime. I've also heard the cycle takes 7 years for every atom to have changed.
But I've also heard that parts of our brain stays the same forever.
If it IS true that parts of our brains stay. Is that the same atoms that keep memories? Or is it true that somehow the new atoms 'learn' the post-7 year old memories? Because that would be really cool ^^