I was learning a bit about the life of a tree, it was a documentary someone was watching while I reread Witches Abroad. To sum up, the living part of the tree is in the thin layers of fluid on the outside, and the solid part inside is basically dead filler space, about as alive as our nails, hair, and topmost layer of skin. The thing about it is that it is there, the tree's dead past is what supports it and gives it the shape the living part of the tree builds on.
Then I thought how much human memory is like that. We start with a thin bit of nothing, and usually some help from others, but after the very start, our past starts to help define what we can do with ourselves. Our past is dead and gone but supports the thin and strongly fragile (oxymoron perhaps, but an accurate description nonetheless) layer of living now of our minds. Stretching our minds now gives our future more possibility, but in the wrong directions can make it easier to break things. Still vital if we want to change the ways we think though.
I've thought a bit more, but it's still somewhat incoherent.