Memory exists as an entity in a formless vast that only appears when summoned. In the sense that in as much as there was life, there would inevitably be memories to uphold, either sad or happy memories.
Why Dimm's own had to come at his death, was inexplicable.
Maybe, because he was still alive, he thought or, so. He was more or less traveling in a vast dome of utter darkness, the only light he received being the history of his past. The memories of what had happened in his past–unfortunately for him, were sad moments.
The moments that flashed from when he was told "Leave here, you bewitcher. This is the reason you do not have a parent," to the moments when his main residence had been the slumps, and his food source had been the fruit of the trees. He didn't know why all these had to be brought to light amid darkness.