I have No Memory Of This Place

Some systems are still shaped by decisions nobody remembers making.

There is a myth about how the width of a Roman war chariot determined the width of Roman roads, which determined the width of railroads, which determined the diameter of the Space Shuttle’s solid rocket boosters. The myth has historical inaccuracies, as myths tend to. But the lesson holds: assumptions encoded into infrastructure take on a life of their own and become rules unto themselves. The original reasoning disappears. The constraint persists. And eventually someone builds a rocket around a road that was built around a chariot, and nobody remembers the horse.

This is what happens to codebases at scale. Decisions made for good reasons in 2019 become load-bearing walls in 2026. The person who made the decision left. The ticket was closed. The Slack thread was archived. The code remains, and it has no idea why it exists.

With human teams, institutional memory usually survives — imperfectly, through tribal knowledge, onboarding docs, and the one senior engineer who’s been there since the beginning. With AI agents, it doesn’t. An agent sees the code and the comments. If neither explains the why, the agent will make its own judgment. Sometimes that judgment is to remove the fence.

This is where we owe a debt to whoever comes next — human or agent. If you made a decision, write down why. Not in Slack. Not in someone’s head. In the code, in the commit messages, in the tests. If the reason for a decision isn’t written down where the next actor can find it, it might as well not exist.

Some things that should not have been forgotten were lost. History became legend. Legend became myth. — J.R.R. Tolkien

Related reading:

• Most Rules Exist for a Reason — on Chesterton’s fence and what to do when you encounter a rule you don’t understand
• Schrödinger’s Syntax — on why encoding the “why” is harder than it sounds