If you open a new chat in the same project in Claude and find that it doesn't remember the last conversation at all, don't suspect that the project is broken. Anthropic's current help is clearly stated: chat contexts in the same project are not shared with each other by default unless you put that information in the project repository.
This is the opposite of what many people have about Project. People often think of Project as "chats in this space will be automatically connected", but Claude's design is closer to "the same set of information and project descriptions for different chats", rather than automatically merging all chat records into one.
So if you just leave important conclusions in the previous chat and don't save them as project instructions or upload them to knowledge, then it's normal for the new chat to not know these contents.
The most effective fix for this type of question is not to keep asking "do you remember" in a new chat, but to reposition the information that really needs to be reused across chats to the right place:
1. Long-term rules are written into project instructions.
2. Materials that need to be cited repeatedly are put into project knowledge.
3. Just a one-time discussion process, stay in the original chat and continue chatting, don't expect the new chat to be automatically inherited.
If you have a lot of project information, don't worry too much about capacity. Anthropic has now added RAG mode to Projects, and when the knowledge base approaches the context limit, it will automatically switch to retrieval enhancement mode to expand. But note that expanding is knowledge, not your ad hoc conversations scattered across chats.
The reason why many people think that "Claude suddenly became stupid" is not because of model amnesia, but because of the confusion between chat memory and project knowledge. The former is thread-level, and the latter is item-level.
In a nutshell, Claude's Project shares "what's in the project", not "everything you say in the project". If this boundary is clarified, the project experience will be much more stable.
