Every client has unspoken preferences. "Jane wants numbers before narrative." "Never mention the Q2 rebrand." "Always CC the ops director." These are the things a CMO learns over months that make the difference between generic and great output.
Behavioral rules live per client mind and inject into every interaction - meeting prep, follow-ups, content drafts. When you switch clients, their rules load automatically and shape Claude's output for the rest of the session.
This is the handoff killer. When a new CMO takes over, they inherit not just data but working knowledge about how to work with each client.