The Notice Board

1. Why does a blockchain trust you, a stranger it has never met?
2. Because it doesn't. It trusts copies.
3. Every entry is written on a notice board, and every house on the street keeps the same board.
4. Change yours and the street ignores you. Change everyone's and you'd need to own the street.
5. Trust isn't asked for. It's made too expensive to betray.
6. Who do you trust more, a bank or a copy?

02). A village street at dusk. Every house keeps the same notice board by its door. A stranger (you) pins an entry; it appears on every board at once. A cheat scribbles on his own board: the street ignores it, his board goes red, the others stay. To change them all he'd have to own the whole street: a price tag rises over the rooftops. Trust isn't asked for; it's made too expensive to betray.