If an engineer designs a computer that computes on encrypted information, from an observer's naive perspective, the entire contents of memory is rewritten with a random value for each step. Yet there is a mathematical relationship between those seemingly random bits and whatever is encoded. Even just using some error correction and non-deterministic parallel processing and it might look pretty much like noise if you don't have the decoder ring.
Something like that is the only explanation I can come up with. Information is stored at a level of abstraction in a structure that is maintained by being continuously re-encoded in the ephemeral computations at a lower level.
Perhaps analog FPGA's are interesting windows https://news.ycombinator.com/item?id=23432601
It might very well be a feature of this drift that old memories or information is gradually adapted. After all evolutionary speaking you wouldn't expect the brain to optimize for archiving but for making fitness optimizing decisions in the world.