Gnomic Dave, you are confusing different meanings of the words "come back", and of the word "we". Of course our materials are recycled, and as I've pointed out elsewhere at different parts of your own career (that is, of your materials), you have been in the core of at least one star (probably thousands), a gas close to absolute zero in deep space, part of countless other living things, trees, birds, insects, bacteria, wood, leaves, non living things like rocks, you have been spewed out of a volcano, you have been to the upper atmosphere and the depths of the sea.

But the "I" that you recognise as your self, that feeling of integrity and unity that separates YOU from other 'yous'... that is the big question. Is it a thing that has colonised your current body from outside, or does it only exist because of the Gnome of today?

I'm in favour of the latter, partly because it explains so much more. Like why my friend's 'soul' departed after his brain was deprived of oxygen, leaving a 'living' but non- responding body. Why a dose of simple chemicals (CH3COOH for example) can change people's personalities. Why people can have such widely different cultural beliefs even when the underlying hardware of the brain is the same. And most of all, I don't remember anything of any previous life.