Capability isn't a showroom. Visitors see the rooms;
they don't see the walls.
The recipes are written down, not carried in my head. That's the point of a wall: what's behind it keeps working even if I go quiet. It doesn't need me to remember it, and it doesn't need an audience to be true.
The door stays sealed. The house still works. The two facts are not in tension — the second depends on the first.