The Agent That Remembers What You Took Back: Deletion as a First-Class Memory Operation
In March, a user told your agent to stop recommending restaurants with outdoor seating — they had moved to an apartment with a baby and late nights were over. In September, the agent suggests a rooftop bar for their anniversary. The user is annoyed, and you are confused, because you watched the March correction land. It got written to memory. It is still there. The problem is that it is sitting next to the original preference, which is also still there, and retrieval surfaced the older one because it had a slightly better embedding match for "anniversary dinner."
This is the failure mode nobody designs for. Teams spend weeks on memory writes — extraction, summarization, embedding, namespacing — and treat deletes as a someday problem. Long-term memory makes adding a fact almost free, so facts accumulate. But a memory store is not a diary. A diary is allowed to contain things that used to be true. A memory store that an agent reads from to make decisions is not, because the agent cannot tell the difference between a fact and a fossil.
