I have this idea for a story, or maybe even a game of some sort.
It involves a magical box that is sort of a time machine, but not in the ordinary sense of the word. It is small, maybe big enough to fit a dozen books or so in, and it features a 12 digit mechanical combination lock.
Once the lock is set, a parallel universe would be created where the contents of the box would then appear at exactly the date and time keyed into the box (for example: 201001011030 would mean Jan 1 2010 @ 10:30am)
In that newly generated universe, the box’s number wheels would instantly snap to zero and the lid would unlock, revealing whatever contents were “sent back from the future.” But anything that happened before that exact moment in time would be identical to the universe that sent the materials back into the past.
This simple narrative construct forms a kernel for countless different stories. But what I have in mind is the idea of some protagonist who is trying to engineer “the perfect life” even though they’d not be able to live it themselves, by repeatedly sending back notes from the future about various life choices.
I can see this taking a tragic turn, where some key “memories” are destroyed or altered, creating a peculiar game of tug-of-war between countless copies-of-copies-of-copies of past and future selves.
The box itself probably would have an origin story too, and figuring out how to construct additional boxes (or on the flip side, figuring out how to destroy the first memory box and halt the endless rollercoaster ride through parallel universes once and for all) could be possible plot lines.
If you had this kind of box, what would you do with it? What problems might you run into? How would it change your view of what it means to be alive?