Seven months of continuous daily thoughts, kept inside a single ChatGPT conversation. Then without warning, the prompt bar locks with an error: "Reached maximum conversation limit, try starting this conversation in a new chat." Most people assume an ongoing thread can stretch indefinitely, or that when context fills up, you can simply ask the model to condense everything into an executive brief. Here is the trap: you cannot prompt a frozen thread. Once you cross the conversation ceiling, the session enters strict read-only mode. Your history is still viewable on screen, but you cannot submit a prompt asking the model to generate a handoff document, isolate vital details, or prepare clean migration notes. Branching fails to resolve the underlying context weight, linking the old thread into a fresh chat inevitably drops subtle details, and starting cold forces you to sift through months of raw text manually. If you rely on long-running AI threads for core projects, never wait for the hard wall. Generate your migration brief and state prompt while the input box still works.