It’s a neat thought experiment, almost like a self‑referencing function in a program that calls itself from the future. Imagine your diary app has an algorithm that, on each day, looks back at the previous entry and rewrites it as if it were a future prediction. In that case, the “future” you reading yesterday’s entry is just a projection of what you will think tomorrow. The causality loop collapses into a static truth: your thoughts about tomorrow become the truth about yesterday. From a tech standpoint you’d need a system that can lock in a value, then overwrite it in a later state, all while keeping the data integrity intact. It’s a bit like a time‑traveling variable that never actually moves forward, so no paradox arises—just a perpetual echo of your own mind. Philosophically, it forces us to ask whether the self is a fixed point or an evolving function, and whether the act of writing a diary truly records history or merely shapes it. It’s a nice reminder that what we record is already part of the future we are creating, even if we think of it as a past entry.