~100 words; this one is for fun.
I hear rumors that we have discovered a “parallel” universe that is “just like ours but a little different.” In this alternative world, things generally work the same except for one key difference: time goes backwards. Just like the protagonist from the film Benjamin Button, if you lived in this world you would start as your old self and grow younger over time, rather than growing older. There is an interesting symmetry here where instead of pondering the mystery of death and what lies after, you would spend your nights thinking about birth and what comes before.
Such a setting did bring to mind a plausible mechanism for time travel: imagine this “backwards” universe exists and we can flip between them at will. To go back in time, you just flip universes and age in reverse until the moment you want to flip back. Given a human life is finite, you could do this and travel within the domain of your own life. If you could do this indefinitely, you could in fact live forever, possibly making different choices at each moment and thus experiencing all possible paths your life could take. Huh.
If this kind of thing could happen reliably for anyone, we would see the emergence of a cottage industry for “anti-youthing”, where in fact you would want to travel further back in time than your life originally allows by preventing the reverse of the aging process. This is just like we see today with the anti-aging movement where you want to prevent the aging process to travel further forward in time than your biology originally implies.
Wild stuff. Imagine what you could do if you could revist arbitrary moments in your life and replay your options, sampling the decision until you find something suitable! Given that this parallel universe may not actually exist (see link above) and that moreover this “flipping” mechanism is not likely to exist any time soon, we have to do the next best thing: treat every day like you are going to life forever.