90-98% of the time I want the LLM to only have the knowledge I gave it in the prompt. I'm actually kind of scared that I'll wake up one day and the web interface for ChatGPT/Opus/Gemini will pull information from my prior chats.
I've had claude reference prior conversations when I'm trying to get technical help on thing A, and it will ask me if this conversation is because of thing B that we talked about in the immediate past